Telescope Recommendations for 2023

Every year I get questions around this time of year from people in the circles I run in asking about buying telescopes. Some are buying for their spouse or partner, some for their kids or nieces and nephews, some for themselves. The people asking me this question tend to have little or no experience with telescopes, but know I do and want my take.

I’ve tried writing this article several times over the past few years. This is the first time I’ve finished it, though I fully expect to revise it a few times.

If you know me, you know I’m long-winded with topics like this, especially in writing. I want to apologize if this seems too long, but I want to make sure people have the information they need, or at least have access to it, to make an informed choice. It’s hard for me to do this in a concise way, so the result is this long discussion.

If you don’t want the details, just look through the headings for what you want to know and go from there.

I am also including a link to a Google spreadsheet with specific recommendations and links. One note on that spreadsheet: the prices I’m showing are list prices, but many of the items are currently on sale, some at a significant discount, and many of them tend to come and go on sale. So if you see something you’re interested in, but it’s a little out of your price range, check the link and see what it’s currently selling for and you might find it’s actually in your price range currently.

Ok, with that introduction, here’s the sections:

Table of Contents

  1. First, Join a Club
  2. A Few Things You Need to Know Before You Buy
  3. Which Brands are Best?
  4. Where do I buy from?
  5. General recommendations
  6. GoTo, or Not GoTo, That is the Question
  7. GoTo Recommendations
  8. What Not to Buy
  9. Eyepieces
  10. Filters
  11. Other Stuff
  12. Solar Observing
  13. Astrophotography
  14. Smart Telescopes
  15. Final Notes
  16. TL;DR: Specific Recommendations <-- Skip to here if you just want recommendations for what to buy.
  17. John’s Telescope Recommendations List Spreadsheet (Opens in new window)

* TL;DR means “too long, didn’t read.” I tend to be verbose and long-winded. If you jump to the TL;DR, you’ll probably find what you’re looking for if you don’t want the more detailed information provided in the body of this discussion.


First, Join a Club

If you have little or no experience with telescopes for stargazing, then my first piece of advice is to hold on to your cash and first find and join a local astronomy club or society. Odds are there’s one in your area, and the cost of membership is usually pretty low. I’ve never seen one in the US that charges more than $50 per year, and most are significantly less. I belong two two clubs — there’s no reason you can’t — and I pay a combined total of about $55 or so per year.

Some people balk at the idea as they don’t want to take the time to go to meetings. Don’t let that stop you. Meetings are only one facet of membership, and are not a requirement – though they can be very informative and a good way to socialize. Unless you volunteer for something, there’s really no responsibility involved in being a member of an astronomy club.

The benefits vary from club to club, but there are a few typical things that most or all clubs offer:

Advice – as a member of a club, you have access to a body of people, many with a lot of experience in the hobby, that are generally happy to help you out and teach you what you want or need to know if you only ask.

Some clubs conduct workshops and classes on various subjects, but in particular on observing and using telescopes. Clubs I’ve been involved in have done classes on the basics of the night sky, how to set up and use your telescope, and simple telescope maintenance, as well as many more in-depth topics.

Many clubs have a piece of property that either the club owns/leases or access has been granted to the club which serves as a dark(er) sky observing site (usually referred to as a dark site). In many, if not most, cases, these sites are well-shielded from the light of nearby traffic and light from things like houses and street lights. Some clubs have facilities at their dark sites such as a “warm room” of some sort (for warming up in the colder months), and restrooms. Some clubs have small observatories with permanently-mounted telescopes – usually something more significant than what the average person can afford). Access to these sites is usually included in membership, though many clubs require some kind of training before you have access to the facility and/or any equipment on-site.

Most clubs conduct regular star parties. These are observing events. Sometimes they’re aimed at members and just socializing while observing, sometimes to help people learn more about their equipment or observing techniques, and sometimes they’re done at the request of an educational or civic organization (schools are a common example, as are groups like the Boy Scouts/Girl Scouts). At these events, several users will set up their telescopes and share their views of the night sky to anyone who cares to have a look. Depending on the type of star party, you may find a few telescopes set up, or dozens. For someone who’s not all that familiar with telescopes, this is a good way to learn more about them in general – get an idea of what they’re best used for – this varies by design and features – how they operate, and get an idea from the owner of the experience of ownership. This is invaluable information when trying to select a telescope for yourself.

Many clubs have club-owned equipment that users can borrow. This can range from simple, low-cost telescopes to some very impressive gear. The equipment may only be available at the club’s dark site, or may be something that members can take home with them, depending on the club and equipment. This is another way people with little or no experience on telescopes can learn more and try before they buy.

In the United States, most clubs are members of the Astronomical League, which is an organization of amateur astronomers. The AL serves in some ways as an unofficial parent-organization for astronomy clubs all over the US. Membership in a local club that’s an AL member club often includes AL membership (which is available without local club membership, but typically costs quite a bit while membership that’s included with a local club is typically very inexpensive and included in the cost). One of the best benefits of the AL is their observing programs, which provide members with the ability to take on tasks and earn awards (typically in the form of a pin and/or certificate). These programs are helpful for better educating observers as well as providing some structure to their observing sessions.

And many clubs have a thriving buy/sell/trade culture where members are often buying and selling equipment between each other. I’ve bought most of my equipment this way, saving literally thousands of dollars over buying new equipment. Most of the time, a user is selling off something they don’t need or no longer use or are upgrading to a new piece of equipment and want to offset the cost by selling an older piece. You can get some very good deals this way as well as find some rare and unique equipment that you’d have a hard time finding anywhere else.

Many clubs also offer gift memberships, so if you’re buying for someone else, this is a good option.


A Few Things You Need to Know Before You Buy

With that out of the way, it’s important to understand that there’s a wide range of telescopes on the market, with prices from under $100 to far more than you would ever dream of expending. You do not have to spend a ton of money to get a decent telescope, but you should be warned that there are a lot of options out there that are really poor instruments with attractive prices and these can often do more to frustrate the owner/user and discourage them from the hobby. I will discuss more about these as we go along.

Before I offer any recommendations, let me just explain a few things about telescopes that will be important to the discussion.

FIrst, the term “telescope” is often used in a couple of different ways. It may be used to refer to the telescope itself, what we refer to as the Optical Tube Assembly, or OTA. This is, as the name implies, the tube that contains the optical elements – either lenses, mirrors, or both – and holds them together along with the focuser. The other way it’s used refers to the combination of the OTA and some sort of mount. The mount, then, is the part that holds the telescope and moves it so you can aim it at what you want to see. To the uninitiated, this might be referred to as the “tripod.” But there are many other options besides tripods, and we’ll talk about them in time.

There are two main types of mount: the altitude-azimuth mount, or alt-az, and the equatorial mount, or eq. Without going into the details, alt-az mounts tend to be the easiest to use and, generally speaking, the least expensive. However, for certain activities, an equatorial mount is superior and may even be required. They are, however, a bit more complex and less user-friendly, particularly for a beginner. Just because a telescope uses an alt-az mount does not mean it’s a cheap or lesser telescope – in fact, there are some very large and expensive scopes that use alt-az mounts. The largest amateur telescope in the world uses an alt-az mount, and some of the most experienced observers I know prefer them.

However, generally speaking, for astrophotography, you need an equatorial mount – and typically a very good one. But astrophotography, or AP, as appealing as it is to some people, is something I strongly recommend someone hold off on until they’ve spent some time learning more about observing and working with telescopes. It is VERY easy to spend a lot of money on equipment for AP and find out you’ve got the wrong equipment for what you want to do (I speak from first-hand experience here). Unless you’ve got some experience already, I would not consider AP a factor in choosing a telescope for a beginner.

If you’re buying a telescope for a beginner, you’re likely to be buying the full kit – telescope and mount. Such kits, for lack of a better word here, come with one or more eyepieces. These are the part of the telescope you use to actually look through it, and are interchangeable. Changing eyepieces is most important for changing the level of magnification and the size of the field of view you get when looking through the scope. When buying a starter scope, you should look to be sure it comes with eyepieces and may even want to add some better eyepieces. We’ll discuss eyepieces more later on and I’ll offer some recommendations.

There’s a handful of more technical terms to know, but I’ll limit it to just a few. The first is the aperture of the telescope. This refers to the diameter of the primary optical element of the scope. By primary optical element I’m referring to either the lens or the mirror, depending on the type of scope, that is used to collect and focus light. Generally speaking, bigger is better here. A telescope with a larger aperture can usually provide better observing, though there are other factors involved. Aperture may be listed in inches or millimeters, depending on the telescope and brand or manufacturer. Typically, at least in the United States, telescopes with apertures of 6 inches or larger are listed in inches, and less than that are usually listed in millimeters. You can convert inches to millimeters by multiplying the number of inches by 25.4, and from millimeters to inches by dividing the millimeters by 25.4 You can do a quick estimate by just multiplying or dividing by 25.

The next term is focal length. This is the distance from the primary optical element to the point at which the light comes to focus. It is almost always listed in millimeters. Focal length is important in several ways, but the most immediate to the novice user is the magnification provided by the telescope. Longer telescope focal lengths mean higher magnification for a given eyepiece.

Focal length is also used to discuss eyepieces. When someone says they’re using a 25 mm eyepiece, they’re referring to its focal length. The longer the eyepiece, the lower the magnification with a given scope. This seems backwards to some people, but it’s just how it works. Shorter eyepieces give higher magnification.

For example, if you are getting 40X magnification in a telescope by using a 25 mm eyepiece, if you switch to a 10 mm eyepiece you get 100X magnification in the same scope. Again, I’ll discuss eyepieces later and a bit more about magnification.

I do want to say here that magnification is NOT something to pay much attention to when buying a telescope. If it tells you how high it can magnify on the box, then it’s probably a poor choice for a telescope and is just using that number to try to excite you when it really is not telling you the whole story. But we’ll come back to that.

One last thing about eyepieces for the moment: there are two common formats. These refer to the diameter of the barrel that slides into the focuser. Those sizes are 1.25 inch and 2 inch eyepieces. While there are some advantages to some 2 inch eyepieces, nearly all amateur telescopes can use 1.25 inch eyepieces, and those that use 2 inch can also use 1.25 inch, while telescopes that are only able to handle 1.25 inch eyepieces cannot handle 2 inch at all.

One last common term used to describe the capabilities of a telescope is focal ratio. Sometimes referred to as the “f number”, this describes the ratio of the focal length to the aperture. If you have a telescope with an aperture of 100 mm and a focal length of 1,000 mm, the ratio is 10/1, or just 10. This is typically displayed as f/10 (hence the term “f number).”

Focal ratio is important to the way the light is concentrated. For a beginner, it’s not a critical factor to keep in mind. However, sometimes the specifications listed on the side of the telescope will give you the focal ratio and sometimes the focal length, and you need the focal length in order to calculate magnification.

There are three main types of telescope design. Here I’m referring to the OTA, the telescope itself. The three types are refractors, reflectors, and catadioptrics.

A refractor telescope is what people often picture in their heads when they hear the word “telescope.” A refractor uses a lens (or, more often, multiple lenses) to collect and focus light. That light is sent down the tube and out the back to the eyepiece.

There are a lot of excellent refractors on the market. However, most of those are very expensive. There are a lot of poor refractors available at very low prices – in fact a lot of the cheapest telescopes are refractors. But these are mostly poor options. I will recommend a few anyway when we get down to recommendations.

Reflector telescopes use mirrors to gather and focus light. By far the most common such design is the Newtonian Telescope, named after sir Isaac Newton. Newtonians, or Newts, use a mirror that’s mounted at one end of a tube to gather light and reflect it up to a secondary mirror that is mounted at a 45-degree angle to redirect the light out through the side of the telescope to the eyepiece. There are other reflector designs, but the Newtonian is the most common, by far.

The main reason that they’re so common is price. The average price of a Newtonian per inch of aperture is much lower, on average, than that of other designs. For example, an 8 inch Newtonian – just the OTA here – can be found for around $400 (give or take). An 8 inch Schmidt-Cassegrain (SCT – we’ll talk about them in a moment) is likely to cost well over $1,000. An 8 inch refractor is very hard to find – only a few companies make them – and the price is likely to be several thousands of dollars, likely over $10,000. Since aperture is typically the most critical specification for a telescope, the Newtonian telescope offers the best bang for your buck.

The third main type of telescope is what is known as a catadioptric telescope. A catadioptric scope, or cat for short, uses a combination of lenses and mirrors to gather and focus light. The two most common types of cats are the Schmidt-Cassegrain Telescope, or SCT, and the Maksutov-Cassegrain Telescope, also referred to as a Mak or MCT.

The chief benefit of catadioptric scopes is that they typically provide a longer focal length in a more compact package. Just as an example, an 8 inch Newtonian with a focal length of 1,200 mm will have a tube that is around 4 feet long or longer. On the other hand, an 8 inch SCT with a focal lengthy of 2,032 mm will typically only be about 2 feet in length. This is due to the way the mirrors and lenses work together to modify the path of light through the telescope, but I won’t go into the details here.


Which Brands are Best?

Before getting into recommendations, I’d like to address a common related question I often get: what brand is best?

On the American market, the main players for the past few decades have been Celestron, Meade, and Orion. There are a number of other brands that are relatively common today, including SkyWatcher, iOptron, Aperture, Astro-Tech, and Zhumell. There is also Tasco, about which I’ll just say this: don’t buy a Tasco, nothing they make these days is at all worthwhile.

But, as it turns out, nearly all of the equipment sold by these brands is manufactured in Taiwan or China by just a few manufacturing firms. For example, the Celestron and SkyWatcher brands are both owned by the Synta Technology Company of Taiwan and the equipment is nearly all manufactured by the Suzhou Synta Optical Technology Company in mainland China. Synta used to also manufacture most of Orion’s equipment, but after a fairly long and bitter legal dispute, Orion has moved their manufacturing business to Guan Sheng Optical (GSO) of Taiwan. GSO also manufactures equipment sold by Astro-Tech, Apertura, and Zhumell, among others.

In many cases, the exact same telescope can be found being sold by two or more brands. Sometimes there are minor differences, but sometimes the only difference is the paint job and brand logo on the tube.

For this reason, unless you’re looking at one of the premium brands (names like Takahashi, Astro-Physics, and Obsession), brand names don’t really mean much and really shouldn’t matter more than price and availability.


Where do I buy from?

I should probably also take a little time to discuss where to buy telescopes and equipment from.

While there are still some brick and mortar shops that sell telescopes, these are becoming few and far between. Some stores that specialize in camera equipment carry them, but since everyone carries around a fairly decent camera in the form fo their cell phone, these are also becoming rarer.

Some so-called “big box” stores carry them on occason. I’ve seen low-end telescopes (which I DO NOT recommend) in stores like Walmart and Target, and I’ve heard of stores like Best Buy carrying them. Generally speaking, if they’re in a retail chain like this, they’re probably not what you want.

One exception to this rule is Costco. From time to time Costco has had some decent telescopes, typically around the holidays. A couple years ago or so they were selling a 10 inch Dobsonian made by Explore Scientific. Though not the best scope out there, this was actually a pretty good one, and the price was pretty good. But Costco also carries some crap as well (as I write this, the stuff ont heir website is all junk). But if you see something similar to what I have in my recommendations, it’s worth considering.

For the most part, if you want to buy a telescope, you’re going to have to order it online. There are several sites, but prices tend to be fairly similar between them. Feel free to shop around and see if you can find it cheaper, but odds are the pricess will be very close everywhere, or, at least, from most vendors.

Most online vendors also offer free shipping on the larger purchases, which is nice becasue otherwise the cost of shipping could be pretty significant.

Here’s a few of my preferred vendors:

Vendor Link Notes
High Point Scientific https://www.highpointscientific.com/ High Point has become one of my go-to recommendations. They offer a wide range of products from most major brands as well as their in-house brand, Apertura, which is one of my top recommendations for Dobs.
Astronomics https://www.astronomics.com/ Another great vendor. Astronomics also runs the Cloudy Nights website, which is a website dedicated to amateur astronomy and has one of the best sets of forums for the hobby, as well as probably the best classified ads. Astronomics also has a house-brand: Astro-Tech, which offers a great line of scopes (though all appear to be made by GSO for them). I definitely recommend them.
Agena Astro https://agenaastro.com/ Agena’s been around for quite some time and has a lot to offer. Another vendor, OPT, recently closed their doors and Agena took over most of their business. They probably have the widest range of products from various manufacturers.
Orion https://www.telescope.com/ Orion’s website, telescope.com, has been their showcase for their equipment for a long time. Since Orion bought out Meade recently, they’ve started offering Meade and Coronado (solar scope) products as well. Orion also has a strong reputation for some of the best customer support in the business… as long as you’re the original owner.
iOptron https://www.ioptron.com/ iOptron’s company site is one of the main places to buy their equipment (mostly mounts), though you can find them on several others as well. One reason I like iOptron is their customer support. Even though I’m not the original owner of my iOptron mount, they have happilly provided assistence. Of course, if I need repairs or replacement parts, they’ll charge me, but getting questions answered has been no problem. In fact, I once e-mailed them about a problem at 8:30 PM one night, not expecting an answer for a day or two, and got an answer by 9:30 PM – they have tech support available at night since that’s when people are using their equipment… very good service, if you ask me.
Celestron https://www.celestron.com/ Celestron isn’t what they used to be, but does still make some excellent equipment, along with some real junk. Their website showcases it and is one of several places to order online.
SkyWatcher https://www.skywatcherusa.com/ In my experience, SkyWatcher is a little harder to find, at least in the US, but their site offers most of their currently available products.
Meade https://www.meade.com/ Meade’s site is still around, though they’re now part of Orion. You can buy from them direct, from Orion, or several other vendors.
Anacortes Telescope and Wild Bird https://www.buytelescopes.com/ Anacortes has been around for ages and offers a pretty wide range of products. They’re one of the few places that you can also get some of the higher-end brands from, like Takahashi and Astro-Physics. Their astronomy101 page is also a great resource for getting into the hobby.
Land Sea Sky https://landseaskyco.com/ While living in Houston, I went to Land Sea Sky several times. They had a lot of great stuff, but their specialty was on higher-end stuff like Takahashi. They’re one of the few vendors for Takahashi products in the US.
Mile High Astro https://milehighastro.com/ Denver-based Mile High Astro has a good array of stuff from some of the most popular brands like Meade, SkyWatcher, and Celestron.
BH Photo and Video https://www.bhphotovideo.com/ BH has been around for quite some time and their focus is more on cameras and photography, but with a wide range of products including a good selection of astronomy equipment. Unfortunately, they sell a lot of junk in with some good stuff.
Optics Planet https://www.opticsplanet.com/ Optics Planet sells lots of non-astronomy-related stuff, including a lot of firearms-related equipment. Mixed in with that, they sell a fair number of Telescopes as well. Not my first choice, but definitely an otpion.
Svbony https://www.svbony.com/ Svbony is an up-and-commer in the hobby. They have a lot of lower-end stuff, but are slowly moving into better and better equipment. I’ve seen some imaging done through their better refractors (apparently GSO-made), and they’re not bad. Certainly worth considering.
ZWO https://astronomy-imaging-camera.com/ Probably the best selection of astro-imaging cameras on the market right now, ZWO is starting to expand more and now offer two new mounts, a smart scope, and some refractors. You could build an entire imaging kit from their products and have a pretty good setup. Not always the best prices, but certainly worth looking at, particularly their cameras.
Starizona https://starizona.com/ Starizona sells a wide range of products and is the only supplier for the Hyperstar Lens kit for Celestron SCTs.
Scope Stuff http://scopestuff.com/ Scope Stuff is a great little outfit that specializes in a lot of random hardware other than the scopes themselves. If you need mounting hardware, they’re the best place I know of to get it. Contact them and they’ll tell you exactly what you need that they have to mount your scope on pretty much any mount. Great service, and good gear.
Amazon https://www.amazon.com Amazon is not my first choice, but they carry a lot of good equipment, mixed in with a TON of junk (like most of their products). Typically, their prices are hard to beat and you get free shipping on most of it if you’re a prime member.

There are plenty of other vendors out there, but these are ones I’ve either ordered from myself or know people who have and would recommend them. Your mileage may vary.


General Recommendations

The number one recommendation I always have for a telescope for someone with little or no experience with them is what is known as a Dobsonian Telescope, or Dob. A Dob is a Newtonian telescope OTA mated to a very simple alt-az rocker-box mount. The simplicity of this design makes it extremely easy to use and less expensive than most other options. Dobs are extremely popular amateur telescopes and used by both beginners and highly experienced experts. A good Dob is a telescope that any amateur astronomer can enjoy.

I recommend an 8 inch version as the best beginner option. 8 inches is something of a sweet-spot with regards to aperture. At 8 inches, you start to get enough light gathering ability and detail resolution to really enjoy the scope, but 8 inches isn’t too large or heavy for most users to be able to carry from their home or car, and they set up and take down in just a few minutes.

The primary downsides to Dobs are that they can be bulky, they aren’t good for astrophotography, and most of them are not computerized. This last point isn’t always a bad thing: manual scopes have less that can go wrong and typically cost less. Learning to find things manually through a practice known as “star-hopping” is not difficult and ends up being more enjoyable in the long run for most users.

So, what will it cost you? It depends on several factors, but you can guestimate a price of around $700 or so for a brand-new 8 inch Dob. Used, you can expect about a 30% price cut. For brand new scopes, most of the major vendors will usually offer free shipping – which makes a big difference. For used scopes, it will vary, but a lot of the vendors will throw in the shipping for orders over a certain amount, regardless if new or used.

If 8 inches is too big or too expensive, then my next recommendation would be a 6 inch version, which is likely to run you somewhere in the neighborhood of $450 to $550.

The next price-step down would be a table-top scope. These are often referred to as “table-top Dobsonian” telescopes, but they’re not true Dobsonians, but I won’t go into the specifics of why. These come in apertures as large as 6 inches and as small as 76 mm (roughly 3 inches). There’s at least one 6 inch model, the SkyWatcher Heritage 150, on the market, currently running about $310. Its little brother, the Heritage 130, runs about $275. There may be a few others in the 130 or 127 mm range by other brands.

The furthest down I’d go is a 114 mm or 4.5 inch version. The standout here is the Orion Starblast 4.5, which lists at $250, though the Zhumell Z114, which runs $240 is pretty much on-par.

These table-top scopes are nice in that they’re very compact. Even the larger 6 inch models are fairly compact and easy to carry around or put in your car and drive to a convenient dark site. You don’t HAVE to have a table to put them on. If you’re happy to get down on the ground, you can use them there, or on the hood of your car (once it’s cooled down). And you can get a small folding table or tv tray, or even a stool, and set it on top of that for use.

Generally speaking, I don’t recommend telescopes under 114 mm / 4.5 inches in aperture. The reason is that the quality tends to go down rapidly – unless you’re buying a higher-end scope – and usually you can get better quality viewing from a fairly decent pair of binoculars for a lower price than a small-aperture scope.

If you have the money for a bigger scope, it’s something to consider. The larger you go, the more light gathering ability and detail resolution you get – enabling you to see more. But the tradeoff is convenience. An 8 inch Dob is reasonable for most people, as far as weight and transportability are concerned. When you step up to a 10 inch, it starts getting less and less convenient. And there’s an old adage: the best scope you have is the one you use the most. A 10 inch Dob is likely to get less use than an 8 inch.


GoTo, or Not GoTo, That is the Question

Ok, so I know some people are going to ask me about computerized, or GoTo, telescopes. And I totally get it: it can be frustrating to have to find things yourself, especially for a beginner. The idea behind GoTo technology seems like the perfect solution here. And I agree that GoTo systems can be really useful. But there’s a lot of caveats as well.

First of all, with rare exception, if you don’t have access to a power source or something breaks down, there’s no manual backup mode. In most cases, you can’t just use it manually if you don’t have power or something breaks down in the mount. In theory, you could flip the clutch release (there’s typically one on each axis) and move the scope around manually, but unless you’re extremely well balanced, you’ll have to hold it in position to view an object, and in most cases that’s just not feasible.

Next, you’re going to pay a lot more, and usually get less telescope for the price. Take, for example, the Celestron NexStar 6SE, which lists at $1,100. It’s a 6 inch SCT on an alt-az GoTo mount. You can get a 6 inch Dob for less than half of that price. You can even get a 10 inch Dob for less than the cost of the NexStar 6SE, and that 10 inch Dob would give you nearly 3 times as much light gathering power and nearly double the detail resolution. You’d be able to see more, and still pay less.

Low-price GoTo mounts can also be fairly unreliable. They have a tendency to break down fairly easily, and their accuracy isn’t always all that great.

And when it comes down to it, they’re often not as much fun in the long run. People who buy GoTo scopes as their first scope all too often end up getting bored with them quickly. They have a tendency to look at the same handful of objects over and over, and then just get bored and put the scope in the closet or garage. The lack of a challenge takes away the interest.

With manual scopes, you have to learn how to find objects manually. And yes this is something you have to learn and practice. But you end up learning more about the night sky and in many cases end up seeing things you’d never have seen otherwise. Many a night I’ve been star-hopping around to find an object and run across something else along the way and spent more time on that something else. Once you learn the techniques of star-hopping, which are fairly easy to learn, and get a little practice in, it starts becoming fairly easy. Then, when you’re observing, you get to add to the experience the thrill of the hunt and the satisfaction of having done it yourself.

Overall, GoTo scopes are not what I recommend for visual observers, particularly beginners.

When it comes to GoTo systems, I also strongly recommend you avoid anything where the mount alone costs less than $1,000. The lower-priced GoTo systems often use cheap plastic in their construction and many use plastic or nylon gears, which are easy to break accidentally – thus making the mount a large, expensive paper weight. And even if they don’t break down, their accuracy is often iffy.


GoTo Recommendations

That said, since some people will insist on a GoTo scope, let me go ahead and offer a few recommendations.

For a beginner, there are a handful of GoTo Dobs on the market. The cost is substantially more than a standard Dob, but if you want a GoTo scope, it might be the way to go. One of the best things about a GoTo Dob is that most of them don’t suffer from one of the major caveats I mentioned above: most of these can be used if the GoTo system isn’t working or you don’t have power. This is not the case for most GoTo scopes, but for GoTo Dobs, you usually can use them as a standard Dob.

A lot of people I know have one of the Celestron NexStar SE line of scopes. There are four different sizes: 4 inch, 5 inch, 6 inch, and 8 inch. The OTAs on these scopes are just fine. The problem is with the mounts, not the scopes. I’ve seen a lot of issues with them, some from internal defects and some from damage caused by users.

From what I have seen and experienced, Celestron’s manufacturing is somewhat inconsistent. With their higher-priced equipment, the quality seems fairly good, but with their low and mid-tier equipment, not so much. WIthout going into great detail and a lot of specifics, I’d be very wary.

As for damage, a lot of people would say “but I’ll take good care of it, so that’s not a problem.” But in many cases it’s due to minor problems that can happen to anyone. For example, I’ve seen people connect cameras for imaging purposes (really not recommended with these scopes, but people do it anyway), and the length of the attachments behind the scope is long enough that if the scope slews to look at something higher in the sky, the camera and additional equipment doesn’t have enough room to pass beneath the scope and hits the base. When this happens, it jams against the base – which isn’t good for the camera or eyepiece or whatever is back there – but the scope will keep trying to rotate the azimuth axis. This can lead to stripping of the gears and/or breaking of some of the mechanical linkages. I’ve seen this happen a few times, and the cost of repairs tends to be expensive enough that most users won’t bother.

The core problem here is that the mechanical parts, particularly the gears, aren’t all that robust and damage can occur pretty quickly and easily, even if you’re trying to be careful.

However, the upside of these scopes is their compactness and portability. The total amount of space they take up is generally about the same as a 6 or 8 inch Dob, but they break down into smaller components, one of which, the tripod, collapses down even smaller. This makes them easier to put in your car and drive off to a dark location.

So, I’m hesitant to outright recommend them, but when they work, they’re pretty good.

I would, however, specifically recommend against the 8 inch version. According to Celestron’s own published specifications, the mount is capable of handling up to 12 lbs of payload weight (e.g. scope and accessories). But, also by Celestron’s published specs, the OTA itself weighs 12 lbs. Technically speaking, by adding an eyepiece you’ve exceeded its specifications. Of course, that 12 lbs limit certainly is set a bit conservatively, and the mount can probably handle closer to 15 or even 20 lbs. But the fact that they push it this much is disturbing, and it would leave them room to refuse warranty service on a mount if it breaks and you were running over the specified limit (I haven’t actually heard of this happening, but it wouldn’t surprise me one bit).

So if you really want to go with this kind of scope, I’d recommend the 6SE over the others.

Meade has a very similar line on the market, the ETX series. Their largest is the ETX125, which has a 125 mm (roughly 5 inch), Maksutov Cassegrain OTA. Again, the OTA is just fine. But here, the mount is even worse than the NexStar SE mounts. The ETX mounts use a lot of plastic and/or nylon in their drive mechanisms, and are much more easily damaged than Celestron’s NexStar SE line. As such, I really recommend steering far from these.

There’s one more line of scopes here I’d like to bring up: the Celestron NexStar Evolution series. These come in three sizes: 6 inch, 8 inch, and 9.25 inch models. All three are Celestron’s Edge HD Schmidt-Cassegrain design. These are a good step up in optical quality, especially for imaging purposes (which I really don’t recommend with these mounts, but that’s part of what the OTAs are designed for).

The NexStar Evolution series has a higher price tag, running from $1,680 through $2,950 (though as I write this there are some significant discounts available). But here, the mounts don’t have the problems that the NexStar SE line does. These, from all I’ve seen, perform quite well and aren’t anywhere near as fragile. If you can afford the price upgrade, these are definitely a better option.

And the Celestron 9.25 inch OTAs have a reputation that stands above most of their others. Though not all that much larger than an 8 inch model, they’ve long been considered superior in quality, often being even more desired than the 11 inch models (which aren’t available on the NexStar Evolution mount). They cost more, of course… but if you’re serious, they’re an option to consider.

If you really want to do GoTo right, your best option is to not go with a complete package, but buy a mount and scope separately. There is a wide array of GoTo mounts on the market, with a wide spread in prices and quality. For my recommendations, I like to break it down into two categories: 1.) mounts capable of around 30 lbs of payload, and 2.) those capable of around 40 lbs or so.

In the 30 lbs category, the two most popular are the Celestron Advanced VX (or AVX) and the SkyWatcher HEQ5. Both are rated for up to 30 lbs of payload. The HEQ5 costs a little more, but has a bit better reputation. Both were built with beginning AP in mind, and have specific features for those who want to get started in imaging. Here, the HEQ5 simply performs better than the AVX, and the price difference is worth it. As with the Celestron NexStar SE line, there’s reports of inconsistency in manufacturing. For every four or five of these mounts, one appears to perform as expected, two or three are relatively decent, but may suffer from minor problems or inaccuracies, and one is an absolute dog. If you get one of the better ones, it’s a great mount. If you don’t, it really won’t be great for AP and may just have a ton of problems.

There are several other players on the market, but only one other I’d recommend: the iOptron GEM28. It’s rated to 28 lbs of payload, so not quite as much, but all of the iOptron mounts I have used have been good performers. Additionally, the hand control for iOptron mounts has a bigger display with more information than either the SkyWatcher or Celestron versions. I find it easier to work with. Its price varies depending on options. The base mount itself with no tripod is only $1,000 currently. Other options include two different tripod options, a hard case, and their iPolar system which makes the process of polar alignment – which has to be done with equatorial mounts – easier and faster. These variants can run the total up to about $1,600, but there are in-between options.

Meade also offers a mount in this class, the LX85, which can handle up to 33 lbs of payload and runs $1,300 currently. To be honest, however, I’ve never used one of these or seen them in the wild, so to speak, so I can’t vouch for them. As such, I’d steer more toward the others.

In the 40 lbs class, there are some great mounts to be found. Here, the price point is closer to $2,000 or more. Again, there’s three options that stand out: Celestron, iOptron, and SkyWatcher.

The Celestron CGEM II is rated to 40 lbs of payload and currently runs $2,050. As with the AVX, there’s some inconsistency, but generally they’re pretty decent performers. I’ve used several and find them to be fairly reliable and are a decent option for beginning to intermediate AP.

The SkyWatcher EQ6-R Pro, however, which can handle up to 44 lbs, is the standout here. It has a stellar (no pun intended) reputation and is highly recommended for beginning and intermediate AP use. It currently lists slightly cheaper than the CGEM as well, at $2,025.

iOptron’s GEM45, which can handle up to 45 lbs, is my personal recommendation, but the price is a bit higher. Again, there’s several options available, from mount head only ($2,320) to a version with upgraded digital encoders (useful for higher precision work) listing a $3,770 (without tripod!). Besides the higher payload (slightly) and superior hand control, one of its additional features is through-mount wiring for accessories – i.e imaging gear. With the other mounts on this list, if you’re attaching imaging equipment, you have to worry about cable management so that you don’t end up tying things in knots and screwing everything up. The GEM45 has USB and 12V power connections on the mount-head itself, allowing you to reduce the cable spaghetti. For visual users, this isn’t all that critical, but for imaging, it’s extremely helpful.

In the case of both Celestron mounts mentioned above, they offer an option to buy the mount alone and to buy bundled with one of their scopes. The scope options vary in price and depending on which mount.

The AVX can be bundled with their 6, 8, 9.25, and 11 inch SCTs, both the standard and Edge HD versions, as well as their fairly new 7 inch Maksutov, their 6 and 8 inch Newtonians, and their 6 inch refractor. I don’t recommend the refractor – it’s not horrible, but just not a great scope, or the two Newtonians. Newtonians on equatorial mounts can be very inconvenient, as the eyepiece ends up in a lot of very awkward orientations making it really uncomfortable for observing (there are some fixes for this, but I wouldn’t suggest this as a beginner option). And the 11 inch SCT is just too heavy for this mount, and I wouldn’t recommend it either. If you’re going to buy the 11 inch, get the CGEM.

The CGEM is available with the 8, 9.25, and 11 inch SCTs, the 7 inch Maksutov, and their 8 inch RASA imaging scope. Any of these would be suitable on this mount.

But there’s no good reason to buy a scope and mount combo other than price. Being brand-loyal doesn’t really matter. It’s fully acceptable, and often preferential, to combine a scope from one brand with a mount from another, with eyepieces from another. With RARE exception, there is no problem with compatibility, as long as you choose the option for the correct mounting hardware (I won’t go into this right now, but there’s basically two options, and if the scope doesn’t come with it, it’s easy enough to get separately).

These past several mounts have all been German Equatorial Mounts. I honestly don’t recommend any alt-az GoTo mounts, though there’s a couple on the market. In my view, if you’re going to do GoTo, you’re best off with an equatorial mount.


What Not to Buy

Ok, now for a few “what not to buy” recommendations. Most of these are what we in the field of amateur astronomy often refer to as “department store” telescopes. The reason for this term is that they can often be found in big-box style department stores. These scopes are often inexpensive and aimed at people who really don’t know anything about telescopes. The brands selling these scopes seem to be more interested in making a fast buck and taking advantage of their ignorance, and less concerned about providing a quality product that will inspire and encourage people to become more active in the hobby.

I’ve seen this kind of scope do more harm than good. People who purchase or receive these scopes as gifts often get frustrated by them and end up storing them in the back of a closet or in the garage, rarely, if ever, to be seen again. On the other hand, someone who has a good experience with a good quality telescope – not even an expensive high-end scope, are much more likely to be fascinated by what they see and go on to pursue the hobby further, often upgrading to better equipment in time.

Ok, so what is it you should keep an eye out for to avoid?

First, if the telescope makes claims on the box or in the ads as to how much magnification it can give you – that’s a dead giveaway. One example is a scope I saw that said “Up to 575X Magnification!” in big letters on the front of the box. This scope was made by one of the big names (I think it was actually a Celestron, but I can’t recall for sure). Between the brand’s strong (lately not as well deserved) reputation, the price, and this kind of comment, it looks to the uninitiated like a good deal. But magnification isn’t what’s most important, it’s light gathering ability and detail resolution. Truth be told, ANY telescope can magnify to 575X, 1,000X, 1 million X magnification – magnification is not limited. But what IS limited is detail resolution. As you magnify, at some point all you’re doing is magnifying a blur. And here, 575X is not reasonable for scopes like this. It’s possible, but it’s going to be a blurry view that doesn’t really show you anything of interest. When they advertise magnification this way, they’re just trying to catch your attention and assume you don’t know anything about telescopes.

Also telescopes that show lots of pictures on the box and try to insinuate that’s what you’ll see. Odds are those images were not taken with that scope, and even if they were (highly unlikely), photography shows things differently from visual observing. This is at the very least being intellectually dishonest.

Most refractor telescopes that come with any kind of mount and a price under $1,000, particularly under $500, and absolutely under $250. Similarly, refractor telescopes with long tubes compared to their diameter – scopes with high focal ratios (I mentioned this early in the article). These are nearly always poor quality instruments and, worse still, the mounts they come on are often very unstable and the scope has a tendency to wobble and shake and make the views through it very frustrating, and even uncomfortable – some people can get headaches from this.

For that matter, any telescopes that come on these kinds of lightweight mounts, especially inexpensive German Equatorial Mounts. As mentioned above, they tend to be very unstable, and they tend to be difficult to use. Steer clear of these.

Any telescope on a GoTo mount under $1,000 (for the package). There are a handful that aren’t horrible (I mentioned the Celestron NexStar SE line, which I don’t recommend, but the lower-end ones are under $1,000 and acceptable). When you buy a low-end GoTo scope you get the worst of both worlds. You get less scope for the price, as more of the money you spend goes to the mount, and those mounts tend to be relatively fragile and prone to problems, and even when they work they’re often not all that accurate. The Celestron NexStar SLT line is a prime example. Steer away from these.

And Newtonian telescopes where the length of the tube itself is significantly shorter than the focal length. A good example of this is the Celestron PowerSeeker 127EQ. The length of the tube is about 500 mm and the focal length is 1,000 mm. This is what we call a Bird-Jones (or Jones-Bird) Telescope, not a true Newtonian, and they have some problems which make it problematic (though I won’t go into the details here).

Sadly, Celestron is one of the worst offenders here: making some of the worst low-end scopes on the market. They have several lines that they sell that are aimed at people who don’t know what they’re looking for, including the AstroMaster, ExploraScope, Inspire, LCM, NexStar SLT, Cometron, AstroFi, and PowerSeeker lines.

To be fair, in many cases the telescopes themselves, the OTAs, are not all bad instruments, it’s the mounts they come on that make them so bad, though some of the OTAs are bad as well. Either way, I’d steer away from them all.

One of the most popular such lines is the PowerSeeker line of telescopes. These are so bad that there’s actually a subreddit devoted to just how bad they are: r/DontBuyAPowerSeeker. These are among the most egregiously bad scope and I cannot stress enough how much I recommend you NOT buy one, particularly not as a gift for a kid. The PowerSeeker 127EQ is one of the best-selling scopes on the market, and a lot of sites give it great reviews. I suspect that a lot of those reviews are actually paid for by Celestron or their parent company Synta. I can’t prove it… but I’d be very surprised if they weren’t.

One I won’t put on this list, however, is the Celestron First Scope series. I won’t recommend them, but they’re at least reasonably decent quality for what they are and what their price is. This might actually be a decent option for a young child.

Meade, Orion, SkyWatcher, and other brands offer some equally bad scopes. I just see Celestron as having the largest range of bad options, which is sad because some of their equipment is actually very good – but you get what you pay for.


Accessories for the Amateur Astronomer In Your Life (Which could be you!)

If you’re looking for a present for someone interested in astronomy, a telescope might not be the best option, or might just not be affordable. I got you covered, fam (sorry, had to say it that way…). Here’s some options for accessories at a wide range of prices.


Eyepieces

And here I have to start with eyepieces. Eyepieces come in a wide range of styles, sizes, and quality levels. If you’re buying for someone who already has a good scope and eyepieces, this might not be the best option for you, but if you’re buying for someone with a brand-new scope that only has the eyepieces it came with, or someone you know doesn’t have good eyepieces, there’s a lot of options here, and not all of them will break the bank.

Again, brands are often not important here. There are, of course, some exceptions. The best eyepieces on the market are arguably those made by Tele-Vue. These can get very expensive, with some being as expensive or more expensive than some fairly good telescopes. But some of their eyepieces aren’t as expensive, and even their low-end eyepieces tend to be superior to most other manufacturer’s high-end options.

Celestron offers several lines of eyepieces. Some of these are pretty good for the price, some are less so. I can’t really recommend their higher-end lines, as there are better eyepieces in the same price range or a little high from other brands. But some of their lower-end options aren’t terribly bad. In particular, the Omni line is reasonably good quality for a fairly reasonable price.

Orion is another source of decent quality at a decent price. The Orion Sirius Plossl line is a decent option. Not the best, not the worst, but not the most expensive either. Orion has several other lines, some aren’t bad, some, like the Celestron higher-end options, are probably not worth the price. The Q70 line are reasonable, as are the EF Widefield, and the Orion Expanse eyepieces are pretty good as well.

While I’m on the Expanse line, there’s another option out here. If you look at the Orion Expanse line of eyepieces, they have a blue band or line around them near the top. If you do a Google search for “gold line” eyepieces, you’ll find some that look almost identical except the blue line is a yellow-gold line. As it turns out, they’re exactly the same eyepieces, just sold under different brand names. Svbony is one such brand. Fairly new on the market, they have some halfway decent equipment, and some real trash. But their gold-line eyepieces are just as good as the Orion Expanse, because they’re the exact same eyepieces. Just like I mentioned with there being a number of Chinese manufacturers that account for the majority of amateur telescopes, the same goes for eyepieces (though I’m not sure they’re the same manufacturing companies, I haven’t unraveled that part of the knot yet). Regardless of the brand, those “Gold Line” eyepieces are usually pretty good quality, and can come pretty cheap.

Meade is another brand I like for eyepieces. While most telescopes come with one or two starter eyepieces, most of them, especially with the lower-cost scopes, are really low quality. Meade does just as bad with their low-end equipment, but their mid-range equipment often comes with some pretty good eyepieces, and those eyepieces are available separately at a pretty good price. The Meade Super Plossl or Series 4000 (same thing) line are pretty good low-priced eyepieces. I have a couple and I enjoy using them from time to time. The Meade 5000 series are also pretty good. I have a set of these and they’re my main eyepieces. I got them used for a really low price, but for brand-new eyepieces that aren’t Tele-Vue, they’re a pretty good option.

Used eyepieces are also a good option in many cases. There’s a lot of used eyepieces out there from discontinued lines. Two standouts to me are the Celestron Ultima (not the newer Ultima Edge,but the original Ultima line with the diamond-checkerboard grips and orange lettering) are some of my favorites. When they came out in the 90’s they were favorably compared to the Tele-Vue eyepieces of the time. I have a few, and they’re extremely good for the prices I paid. They come up on the used equipment market fairly frequently, and I definitely recommend them.

Older Meade 4000 and 5000 series eyepieces also come up often, as do their less popular 3000 line. Those 3000 eyepieces aren’t bad either, and can often be found cheap if someone is selling them.

There are, of course, other options out there, but these are the brands and lines I have used and recommend. But then this leaves the question: which sizes?

As I mentioned before, there are two common barrel sizes: 1.25 and 2 inch. If you have a telescope with a 2 inch focuser, then you can use any of them. If not or you’re not sure, stick with 1.25 inch. 2 inch eyepieces really only give you a benefit with longer, lower magnification eyepieces, generally things over 25 mm, and especially the 30+ mm range. For 1.25 inch eyepieces, I wouldn’t usually recommend getting focal lengths longer than about 30 or maybe 35mm, though they do make them longer (I have a Celestron Omni 40 mm, and it’s ok, but I generally use my Ultima 30’s instead in a 1.25 inch focuser).

Most people, especially beginners, really don’t need more than 2 or 3 eyepieces. It’s generally far better to spend more on a couple of pretty good ones than a bunch of cheaper ones. The main things you get from switching eyepieces are changes in magnification and the size of the field of view. Most people won’t step-up the field of view in small increments, so having a wide range of sizes isn’t usually all that useful.

Typically, for any given scope, there’s two or three levels you need. You want a wide-field view for larger objects (especially a lot of star clusters and nebulae), which means a long focal length. You want a high-magnification view for things like planets and some smaller deep sky objects like planetary nebulae, and this means a short focal length. And then it’s nice to have something in-between. When I’m observing in my main visual scope, I tend to use a 40mm 2 inch for wide views, a 25m 1.25 inch for intermediate views, and a 14mm for higher magnification. With a Barlow lens (I’ll come back to this in a moment), I can double the magnification of all 3 of those for 6 options, but usually only use this on the 14mm to get an effective 7mm. This is all I really need.

My recommendation, then, is to get something like a 30mm for wide field, a 10mm for high magnification, and maybe a 20mm or so for in-between. Or you can skip the in-between and get a Barlow.

What is a Barlow? A Barlow lens is an optical element that effectively extends your telescope’s focal length. Sometimes you’ll hear people refer to them as lens doublers or eyepiece doublers, and this is a reasonable description.

Let’s say you’re using a telescope with a focal length of 1,000mm and a 25mm eyepiece. To calculate your magnification, divide the telescope’s focal length by that of the eyepiece, so 1,000 mm / 25mm gets you 40X magnification. If you switch to a 10 mm eyepiece, then you get 1,000 / 10 or 100X.

Let’s say you have a 2X Barlow lens. A Barlow will have a barrel that slides into the focuser, just like an eyepiece, and on the other side have an opening to accept an eyepiece (and usually a thumb-screw to tighten it and hold them together). When you insert the Barlow into the equation, you multiply the telescope’s focal length by the Barlow’s factor. So with the above examples, you would have 1,000 X 2 and divide that by 25, so you’d get 80X with the 25mm eyepiece, and with the 10, you’d get 1000 X 2 divided by 10 for 200X. Or you could just divide the eyepeice’s focal length by 2 and multiply that by the telescope’s focal length – you get the same result.

Most Barlows are 2X Barlows, but I’ve seen them as low as 1.25X and as high as 5X. Generally speaking, I recommend 2X over the others, as they tend to be most common, and therefore less expensive, and don’t give you as big a jump (for example, if you have a 10mm and a 30mm eyepiece and a 3X barlow, the 3X barlow would make the 30mm act like a 10mm and that doesn’t add to your options). And while I mentioned in another section that you can magnify to infinity, pretty soon you’re just magnifying a blur, so 3X or more really doesn’t make that much sense for most users.

Like eyepieces, Barlows come in a variety of quality levels. I would not recommend a cheap Barlow, as you can often find with low-end eyepiece lines and may come with a set. If it costs less than $100 at full-price, it’s probably iffy (though often you’ll find them on sale for less). But a pretty decent Barlow is nice to have in your kit.

Understand, however, that it’s always best to have the level of magnification you want without a Barlow. The more glass in the path of light, the more likely there is to be distortion or other problems. But a good Barlow will definitely be a useful tool from time to time, just don’t expect it to be just as good.

As I mentioned before, twice now, there are limits to the benefits of magnification. The aperture of the telescope makes a big difference here: larger apertures will let you magnify more before the blur becomes noticeable or severe. There’s a general rule of thumb that the highest magnification a telescope can provide is roughly 50 or 60X per inch of aperture (or 2 to 2.5X per millimeter). So a 5 inch scope should be good for around 250 to 300X, while an 8 inch scope should be good for 400 to 480X.

There are a couple of caveats here. First, is that this will largely depend on the atmospheric conditions while viewing. The transparency and steadiness of the air (including at higher altitudes above you) makes a big difference. This is why most major observatories are built at higher altitudes in deserts these days, where those conditions are better for observing. For most of us at sea-level or thereabouts in areas with average weather conditions, the maximum useful magnification on a regular basis might be closer to ½ or ⅔ of that value. Where I used to live near Houston, views in my 8 inch scope were often getting pretty fuzzy around 200 or 250X, though on occasional nights with really good astronomical seeing conditions I might push it closer to 300 or 350X.

Tele-Vue actually says that anything over 350X, regardless of aperture, is not recommended. And since that means they’re essentially recommending you not buy a lot of their eyepieces, I would call that pretty good advice. I have seen some views at much higher magnification levels through large scopes a few times, but those were on very rare and exceptional nights of observing. I wouldn’t waste money buying eyepieces to push your magnification to the limits, not if you want good views.

One last thing about eyepieces: please, for the love of all that’s holy, do NOT buy someone an eyepiece “kit.” There’s a bunch of these on the market. They look like a deal: 4 or 5 eyepieces, maybe a Barlow, and often some filters, all in a nice padded case, for a price that’s much less than buying them individually.

But most of the time these are lower-end eyepieces, and you really don’t need all 5. And the filters, which can be useful for planetary viewing, often aren’t all that necessary. In short, these are usually a waste of money. Some of the higher-priced kits might be ok (again, I have a Meade 5000 series kit… but I got it really cheap), but I still wouldn’t generally recommend them. Buy two or three decent eyepieces ala-carte and you’ll likely be happier.


Filters

Ok, I just mentioned filters. Should you get them?

There’s a few main types. The most common are colored filters. These are really only used for planetary observing. Different colors are useful for bringing out different features by increasing contrast. For example, some blue filters make it easier to see Jupiter’s Great Red Spot. These do nothing, however, for deep sky objects like nebulae or galaxies – and, in fact, make them harder to see overall. The vast majority of these filters screw on to the end of the eyepiece barrel (which inserts into the focuser).

Next are nebula and narrow-band filters. A narrow-band filter blocks all but a specific type of light. A prime example here is an OIII filter. OIII is also known as doubly-ionized oxygen. This emits a very distinct glow at two separate wavelengths of light: 495.9 nm and 500.7 nm. This can be found in certain nebulae, and those nebulae can often be hard to see otherwise, because they’re so faint. What the OIII filter does is block nearly all light except the light at those wavelengths (well, a little bit above and below each), meaning that the light you see through the scope is limited to just that light. This can make those nebulae that are otherwise too faint to see among the background of the sky, visible through the filter (though still very faint, there’s little or no other light to contend with).

There are several such narrow band filters, though they’re more commonly used for imaging purposes. For viewing, however, an OIII filter can be nice to have. The other common ones are Hydrogen Alpha (Ha), Hydrogen Beta (Hb), and ionized Sulphur (SII). Again, however, they’re more common for imaging than visual use.

A nebula filter is usually a combination of more than one of these, typically allowing for OIII and Ha, but sometimes including Hb and/or SII. These are the most common wavelengths in nebulae, so the filter helps block all but those wavelengths to make nebulae easier to observe. This isn’t a bad thing to have in your kit, but not something I’d rush out for if you’re still a beginner.

A moon filter or neutral density filter is nice to have if you want to look at the moon. What these do is act like sunglasses for your telescope – cutting down the harsh brightness of the moon while giving you the detail resolution and magnification the telescope can provide. There are some polarizing filters that do essentially the same thing, allowing you to dial in the polarization how you like. They can also be useful on planets when planets, particularly Jupiter, are at their brightest.

Solar filters are a bit of a different beast, and I’ll cover them a little later. Let me only say here that solar filters that screw on to your eyepieces should never be used. These are hard to find these days, but were relatively common a few decades ago. They’re very, very bad options for solar viewing. If you have one, treat it as a curiosity and collector’s item, but do NOT use it.

Lastly there are what we call Light Pollution Reduction (LPR) filters. Another name is “sky glow” filters. These are a nice idea… but should be taken with a grain of salt. They work by blocking the most common wavelengths of light associated with light pollution. However, this is becoming more and more of a problem as more and more lighting is done with LED lights. The biggest culprit for light pollution has always been streetlights. For several decades the majority of streetlights have been sodium-vapor lights (either high-pressure sodium – HPS or HPSV – or low-pressure – LPS or LPSV – lamps). These were fairly standardized and emit a very specific spectrum of light which was generally not in the same wavelengths of most of the stuff we like to observe in the night sky. As a result, it was fairly easy to build filters to block these wavelengths and let everything else pass through, which helped reduce the effects of light pollution (though not eliminate them). They weren’t a miracle cure, but they could help.

LED lights put out different spectra of light, and there aren’t really any standards that are consistent here. As such, LPR filters aren’t all that useful in a lot of places anymore, particularly large cities which have converted a significant portion of their street lighting to LED. As a result, I generally don’t recommend you waste the money on these. But if you find one really cheap, you can go ahead and give it a try.


Other Stuff

There’s a lot of other accessories out there for the amateur astronomer. One helpful one is a red flashlight. You see these used by astronomers a lot because regular white light flashlights can mess up your night vision. In the dark, your eyes adapt in a few ways to more efficiently collect light. It can take a while, sometimes hours, for your eyes to get really well adapted. Then someone comes along and flashes a light in your direction and suddenly your eyes rever to their normal, non dark-adapted state

Red light has less of an effect here, which is why you’ll also see it used by other people working in the dark, for example the military on board warships often go to red light at night during combat and exercises.

Red flashlights, particularly those that aren’t overly bright or can be dimmed, are really useful for astronomers. There’s a lot of options on the market, and there’s no good reason to stick with those made by telescope brands like Celestron. I generally recommend one that doesn’t have a white light also – as it’s too easy to accidentally turn on the wrong one. And red light headlamps can be even better, giving you freedom with your hands when you need it.

For people with GoTo telescopes and/or doing astrophotography, a battery-based power source can be useful. Celestron and a few other companies make them specifically aimed at astronomy, but you can often get a cheaper option. A lot of jump-start packs for cars work just as well – in fact they’re often exactly the same, maybe with a few different features. Most telescopes don’t need a lot of power, and these packs can often run your scope, and often some additional equipment for a night or two without a recharge. Using a jumpstarter pack gives you the flexibility of having that feature if you need it, or at least making it useful beyond astronomy. Some of those also come with air compressors for your tires and other features. The thing to look for here is the one with the highest number of amp hours in the battery (you might have to dig through the specs to find it). But most that are capable of jump-starting a car will work fine.

Other accessories to consider are folding tables and chairs, hoodies with dark hoods that can help block stray light and keep you warm, gloves that are thin but keep your hands warm, and observing aids like planispheres and star charts.


Solar Observing

I mentioned solar filters briefly before. Let’s dig a bit deeper now.

Besides the eyepiece filter I mentioned before and once again would like to stress you should NEVER use, there are two main types of solar filters.

The first, most common, and least expensive is what we call a white light solar filter. These are usually made out of either mylar film or specially-coated glass. They block nearly all of the sun’s light, allowing just a little to get through to the optics of the telescope. These filters are essentially good for observing two things: sunspots and transits. A transit is when something passes between the observer and the sun. An eclipse is a specific type of transit. There are also transits of Mercury and Venus. The Venus transits happen in pairs that are a few years apart every hundred and something years. The last was in 2012 and the next won’t be until 2017, so it’s not likely any, if many, people reading this will see it. Transits of Mercury happen a lot more often, and the next will be in 2032 followed by one in 2039. Other objects like satellites, especially the Hubble Space Telescope (but not the Webb), the International Space Station, and high-flying aircraft can also be viewed this way.

White light filters vary in price, depending on aperture and material, but usually are available for under $100 for small to medium sized amateur scopes, and a bit over for larger scopes. You can purchase the film or glass and make one yourself if you’re the DIY type, you just need to be very careful that you construct it properly so that no unfiltered light enters the telescope. Unfortunately, most of these filters are designed to fit a specific aperture of telescope, so if you have two or more different telescopes with different sizes, you’ll need multiple filters to use them with them for solar observing.

The other kind of solar filter is a narrowband type, the most popular being the Hydrogen Alpha solar filter. I mentioned narrowband filters before, but these aren’t the same. Narrowband filters for observing typically have a bandpass – the width of the band of wavelengths of light allowed through – measured in a few nanometers. A good narrowband filter of this type might only allow a 3 nanometer band through, for example. But narrowband solar filters only allow a bandpass measured in angstroms – tenths of nanometers, a very tiny band of light.

This kind of filter allows you to see surface detail on the sun such as granulation and solar prominences (these are the flare-like bits you can see on the edge of the sun in some images). This kind of system actually has two parts. The first is an energy-rejection filter which hugely reduces the amount of light that passes, and the second is what is known as an etalon, which is a special filtration system that can be adjusted – tuned- to get a precise wavelength from.

These kinds of systems tend to be much more expensive, and often the telescopes that come with them are designed only for solar observing, though there are some add-on kits for other scopes. Most of these are also hydrogen alpha systems, though there are a few for other wavelengths, though these tend to be more rare and even more expensive.

The cheapest option here is probably the Coronado PST (Personal Solar Telescope) made by Meade. Currently, these run around $900. They’re small, only 40mm scopes, but here aperture isn’t nearly as critical. Coronado/Meade make a few others up to 90 mm, which can run up to around $10,000, which is far out of most people’s budget. The PST, though, while not cheap isn’t a bad scope. While it is a one-trick pony, it still could potentially get more use as the sun is up all day, when most of us are awake and able to view it, and the only thing then stopping you is clouds. With a major eclipse coming up in 2024, this is something worthy of consideration.

Lunt Solar Systems offers their own line of solar scopes, starting at about $750 for a 40mm. Lunt also offers a line of “universal” telescopes that are designed for solar, night time, and nature observing, though they don’t come cheap.

There’s one more common option on the market for narrowband solar filters, and that’s the Daystar Quark. This one works with a regular telescope and inserts as an eyepiece, though it’s not the same thing as a solar eyepiece filter that I warned against. These are full filtration systems and safe to use. However, they can overheat, depending on the scope, and may need time to cool back down unless you also purchase an energy rejection filter. They’re not cheap, running about $1,300 for the basic model, but they are a bit more versatile. The company also makes them in multiple wavelengths, not just hydrogen alpha. It’s not a bad option if you’re up for the cost.


Astrophotography

And now, for the section so many people have been waiting for. Astrophotography.

Let me first say this: AP is not easy. Ok, sure, you can hold up a cell phone camera to an eyepiece and snap an image of the moon or Jupiter and you might end up with a tolerable image. But to get anything that is actually pretty decent, it’s not easy and it’s rarely cheap. It doesn’t have to cost a million dollars, but it’s likely to cost more than you want to pay.

I cannot recommend that people just getting started with amateur astronomy get right into AP. To me, this is like learning to fly airplane in a Boeing 747 instead of a single-engine propeller plane like a Cessna 172. To me, it’s a recipe for failure, or, at the very least, severe frustration.

AP is a combination of science, engineering, and art. If you want to produce good images, you need to be patient and tenacious. You need to be able to suffer frustration, sometimes pretty extreme frustration, and persevere.

In my experience, probably more than three-quarters of the individual image exposures I capture end up being discarded. And with what remains, I often spend countless hours in the processing phase to get to a point where I have an image I’m fairly happy with. Even then, it’s common for me to end up going back time and time again to re-process and refine the image. For most of us, an image is never really complete.

While for visual observing, there are telescopes that are reasonably good for a little of everything: planetary, lunar, and all sorts of deep sky. But for imaging, this really isn’t the case. You need to tailor your equipment for the type of images you want to capture, and this means that either you specialize in one type or get several different sets of equipment.

If you’re wanting to get started or buying for someone who wants to, then I do have some suggestions, but you’ll find that the price for imaging is going to be significantly higher for visual observing. There are some ways to cut costs, but it’s almost always going to end up costing more than you think.

For AP, you need three main pieces of equipment: the camera, the telescope, and the mount. Pop quiz: which of these three is most important?

The answer surprises a lot of people. The most important piece of equipment for AP is the mount.

Let me put it this way: you could have a million-dollar top-of-the-line telescope and a million-dollar top-of-the-line camera, but if you don’t have a decent mount, you won’t get good images. On the other hand, a mediocre camera and telescope, when mounted on a good mount, can produce decent images.

In other words: it’s the mount, dummy.

There are two main challenges involved in AP that the mount is crucial for overcoming. The first part is that the targets we are trying to image are mostly very faint. The moon and planets tend to be fairly bright and are somewhat easier to image, but for deep sky objects like galaxies, nebulae, and star clusters, the challenge is always how faint they are. We need a telescope not to magnify them so much as to collect enough light to make them visible.

With AP, we nearly always use long exposures to capture these targets, keeping the camera shutter open long enough to “soak up” (so-to-speak) enough light to make a good image.

But there’s another challenge that complicates matters: these things are moving.

Because of the rotation of the Earth, stars, planets, the moon, galaxies, nebulae, etc… all rise and set, just like the Sun and for the same reason. If you look up at the night sky, it may appear that the stars are not moving, but if you keep watching, you’ll see that they are drifting East to West through the night. If you point a telescope that doesn’t have any kind of tracking ability at one and use a reasonably high magnification you can watch them move through your field of view – and the higher the magnification (and smaller the field of view) the faster they appear to move.

If you’re trying to take a long exposure image and the subject is moving, you end up with a blur or streak. If you’ve ever seen “star trail” photographs – photos taken, usually pointing toward the North, that show the trails of stars as they move across the sky – then you can see a clear example of this happening.

If we want to capture an image of something, we need a way to keep the camera – and in this case the telescope – pointing at that object and following it very carefully across the sky. And this is why the mount is so important for AP.

If you’re only interested in the moon and planets, you can get by with a lower-cost option and may even have some success with a manually-operated scope, because you don’t need really long exposure times. You can also often get away with an alt-az mount. But for anything requiring exposure times of a few seconds or more, you almost certainly need an equatorial mount. Not only that, you need one with very smooth and accurate tracking motion and for it to be precisely aligned with the celestial pole.

Before I get down to mount recommendations, let me say a little about the scope and camera. The combination of scope and camera will dictate the size of the field of view you get. The longer the focal length of the scope, the smaller the field of view with a given camera. Alternately, the larger the camera’s image sensor – here I mean its physical dimensions of width and height, not the number of pixels – the wider the field of view. You want to balance these two factors based on what you intend to capture in your images.

Larger telescopes and cameras, of course, will be heavier than smaller ones. And this is a concern for the mount. As discussed previously, mounts can only handle so much payload, and so you need to keep this in mind when selecting your AP equipment. Further, one of the most common rules of thumb you will hear in the AP community is that you should limit your imaging payload to ½ or less of the mount’s maximum capacity. So if you have a mount that is rated to 30 lbs, you want your imaging scope, camera, and other accessories to weigh 15 lbs or less in total. This isn’t a hard rule, there is some wiggle room, but it’s good advice to follow or, at least, keep in mind.

And the smaller the field of view you want for your images – e.g. if you’re trying to capture images of galaxies, most of which tend to be fairly small in angular size – you need more precision than if you’re capturing wider-field images. Most likely, if you’re capturing wider-field images you can get away with less expensive mounts and lower payload capacities, but if you’re trying to capture narrower-field images, you are likely to have to look at more expensive options.

In order to give recommendations, I’m going to focus (no pun intended) on two types of imaging targets: wide-field targets which would include things like the North America Nebula and the Andromeda Galaxy; and narrow-field target which would include things like the Crab Nebula and the Sombrero Galaxy.

For wide-field, you can probably get by with a lower-priced mount. Here, the SkyWatcher HEQ5 is probably the best option. It has a proven track record with beginning astrophotographers and it’s price isn’t too crazy (when compared with a lot of other options). It’s also fairly consistent in quality.

The Celestron AVX would also be an option, but as discussed previously, consistency can be a problem here. The AVX was specifically designed to overcome some of the shortcomings of its predecessor, the CG-5-ASGT, which had about the same payload capability. For those that work as expected, this is a decent way to go. But with so many that don’t live up to that expectation, I’m hesitant to recommend it.

The iOptron GEM28 is another good option here. If I were in the market, I’d likely be torn between the GEM28 and the HEQ5.

For the narrower-field options, if you can afford the iOptron GEM45, it’s probably the best option, but it’s noticeably more expensive than the SkyWatcher EQ6-R Pro or the Celestron CGEM II. The EQ6-R pro is slightly cheaper than the CGEM II, and has a better track record, so I would certainly go with it over the CGEM, but if you can afford the iOptron mount, I’d personally choose it over either of them.

As it turns out, there are a few cheaper options, but they have some limits. For really wide-field stuff, like trying to capture an entire constellation or at least a patch of sky a few degrees wide, with a fairly lightweight scope and camera or just a camera and lens, then there are some camera tracking mounts that aren’t bad options. Here, the SkyWatcher Star Adventurer series starts around $400, and the iOptron SkyGuider Pro is about the same. Once again, I prefer the iOptron, but I’ve never personally used either, just seen their results, which are pretty equal. But they are really limited in payload and features, and their light weight makes them more susceptible to breezes and vibrations. On the other hand, they’re much smaller and more easily packed up and taken wherever you want, so pros and cons.

When it comes to cameras, a lot of people get started with a DSLR (or lately, mirrorless, but I’ll just use the term DSLR for now). This is not a bad way to get started, but has its limitations. If you already have a DSLR, then feel free to try it out. But I wouldn’t go out to get one if you don’t already have one, there’s better options at reasonable prices.

Most people these days seem to use their phones as their primary camera, and DSLRs, while they still have their place in the industry, aren’t as popular as they used to be. Unless you have other reasons you really want a DSLR, again, not what i”d recommend. I have two DSLRs and very rarely get either out for regular photography, and not often for AP (since I have better cameras for that). If you DO want to get a DSLR anyway, I strongly recommend Canon over Nikon, and both of them over any other brand, for AP use. Canon has been very friendly with the AP community from the get-go, while Nikon has been less so and only more recently has started paying attention to the niche. It’s easier, and usually much cheaper, to find software, accessories, and information for using Canon cameras than it is Nikon. I have seen some people using Sony cameras with some level of success, but Canon is the easier and usually cheaper option overall.

But better than a DSLR is a camera designed for astrophotography. There are several brands out there, but lately there’s one that has been getting the most attention, and that’s the only one I’d really recommend for a beginner.

ZWO makes a pretty wide range of astro imaging cameras under their ASI line. Their prices are reasonable for what they are, and the quality and reliability is pretty good. No one else I’ve seen offers the same level of quality at a better price. You might find cheaper, but not by a lot and it’s likely to be a lot lower quality.

Prices run from around $200 for their lowest-end stuff, primarily aimed at planetary and lunar imaging, to a few thousand for their higher-end stuff. There’s several in the $500 to $1000 range that would be good for a beginner. Which one you’d want would really depend on the size of the image sensor based on what you want to do with it. I won’t list specific models, just recommend. Most major vendors of astronomy gear sell them and you can buy direct from their own website.

If you have a much bigger budget, then you might look at the Santa Barbara Instruments Group (SBIG), or Finger Lakes Instrumentation (FLI). Both make extremely good professional-grade instruments. Of course, the price tag associated reflects this. SBIG has made a lot of mid-range stuff in the past, that was reasonably affordable for amateurs (at least some amateurs), but has moved away from that and more into professional-level research-grade equipment. Still, they come up on the used market relatively often, so they’re worth considering.

When it comes to telescopes for AP, you might be tempted to think bigger is better. This is actually not always the case. In fact, it’s often not.

For imaging, the most important factor is usually focal ratio, not focal length or aperture. This is because focal ratio determines the way light is concentrated on the image sensor, which, in turn, will determine how long your exposures will need to be. The shorter the focal ratio, then, the better. Due to the inverse-square rule, if you keep the aperture the same, but double the focal length (and thus, ratio), you quadruple the required exposure time. This is why you may hear of shorter focal ratio telescopes referred to as “fast scopes.”

Unfortunately, shorter focal ratios lead to more noticeable problems with various optical aberrations. For Refractors, where chromatic aberration is the key problem, the longer the focal ratio, the less noticeable the chromatic aberration. With Newtonians, its coma aberration. And with Schmidt-Cassegrain and Maksutov-Cassegrain scopes, it’s spherical aberration. There are others, but these are the most common.

For these aberrations, there are correcting lens options. You need a coma corrector for a fast Newtonian, and a field-flattener for an SCT with a shorter focal ratio. For refractors, you want an apochromatic refractor. This, of course, ups the price.

And, again, you need to consider the total focal length for determining field of view.

So let me offer a handful of recommendations with all of this in mind:

For lunar and planetary imaging, you will probably want focal length for narrower fields of view (akin to magnification) and detail resolution. An 8 inch SCT like the Celestron C8 is a good option here. Using a DSLR or other camera with a larger image sensor won’t let you fit the entire moon in, so you might want to add a focal reducer. Celestron offers an f/6.3 reducer for its regular SCTs and a f/7 reducer for its Edge HD scopes. With a small-sensor camera like th e ZWO ASI120MC, you have a good option for imaging Mars, Jupiter, and Saturn (the other planets, largely, aren’t good targets for imaging). With a good quality Barlow lens, you can get an even smaller field of view. And with common imaging techniques, you can overcome a lot of the blurriness associated with the limits to angular resolution (which is why visual observing gets blurry as you magnify more). Even a 6 inch SCT like the Celestron C6 would be a pretty good option here. But, of course, neither scope is cheap.

For deep sky imaging, there’s some lower-cost options as well as higher priced ones. The Celestron C8 and C6 can be used for deep sky, but the long focal ratio makes that a problem. Even with the f/6.3 reducer, it can be difficult. You need a really solid mount in a case like this, so it’s probably not your best bet.

You’ll find better options for wider-field imaging. My top recommendations here would be one of the several options available from Astro-Tech. They offer several different refractors which are really geared toward AP with some prices being very reasonable.

The best one of the bunch for a beginner is probably the AT72ED, which lists at $520. This is a 72mm ED doublet refractor. The best refractors are 3 or 4 element apochromatic refractors, which can reduce chromatic aberration to the point where it’s not perceptible. This is a 2 element achromatic, but they use a special kind of glass that dramatically improves the reduction of chromatic aberration, close to that of an apochromatic scope.

That’s a whole lot of jargon to say this is a pretty good imaging scope, particularly for the price.

You will want to add the additional field-flattener, which is another $140, though you can probably get by without to start. The flattener is also a reducer and widens your field a bit more, as well as giving you a lower focal ratio for faster imaging. Being a fairly small and light scope, it’s a good choice for the lighter mounts out there.

course, if you’re really on a tight budget, you can get a start with something even cheaper. Now I don’t outright recommend this scope for imaging, but it would give you something you can use to get started with. You won’t get good images from it, but you’ll get halfway decent ones you can learn on. And this scope is the venerable Orion ST80. The list price on these is a whopping $110, but you can often find them on the used market for significantly less. They’re a basic 80mm f/5 doublet refractor, and they’ve been used as finder scopes and guide scopes for ages, and there’s a lot of them out there.

Orion now offers a newer option, the CT80, which has the same specs, but is even cheaper, at only $100. I think it uses a bit more plastic in its construction, however, so it might not be quite as durable, but it should be fine for a beginner. And once you upgrade, it can become your guide scope for an autoguider.

I’ve used the ST80 for imaging, just to see how it does. And while there’s definite issues with chromatic aberration, it still works ok. If you happen to have a photo tripod around, it also is great for a quick wide-field view or for terrestrial use (e.g. birdwatching and the like). Again, not a great scope, but a cheap one.

If you have the budget for it, there’s another option out there, actually two. The first is the Celestron Edge HD series, namely the Edge HD 8 inch. These are an upgraded version of the C8 with improved optics, particularly for imaging. While the 8 inch version has a native focal ratio of f/10, there’s an optional reducer that drops it to f/7. Unfortunately their low-cost f/6.3 reducer won’t work here, due to the built-in field flattening, and the reducer designed for this scope is for this one only, not the bigger or smaller scopes. And f/7 is still a pretty slow scope for deep sky. But wait, there’s more!

These scopes – actually, I believe, most of the Celestron SCTs these days – come re-configured for the HyperStar imaging system. This system allows you to remove the secondary mirror, add a specially-designed correcting lens, and mount the camera in its place. This drops your focal ratio for imaging to f/2 – which is simply insanely fast. Let’s say you need 1 minute of exposure time at the full f/10 to get a good image of your target. With the .7 reducer, you could do that in 30 seconds. If you could drop to f/5, you’d get it in 15 seconds. With HyperStar, you get it in 2.5 seconds. Why? It’s all about the way the light is concentrated on the image sensor. You get a much larger field of view and a lot more light concentration. The downside is that the objects you’re imaging will be smaller in that field of view, but you still can do some very fast imaging.

The HyperStar kit isn’t cheap, however. They’re only available from Starizona and the one for the C8 or Edge HD 8 inch runs $1,000. They’re specific to the model of scope, and not compatible with all cameras, so you’d need to do your homework. But if you have the money, they can be a real game-changer.

Celestron has also developed a line of scopes based on this concept which are essentially a permanently-configured version. Known as the Rowe-Ackerman Schmidt Astrograph, or RASA, they provide essentially the same performance as the Edge HD8 with the HyperStar system. They’re not as cheap as the Edge HD8 (not that it’s cheap), but they’re cheaper than buying the scope and HyperStar system separately. The one main downside is that they’re a one-trick pony: only usable for imaging, not visual observing. But if you’re serious about imaging, it’s a scope to consider.

In the long run, if you want to get into imaging, I would recommend a budget of no less than $3,000 to get started, and that’s going to be tight. You could possibly go cheaper, but you’ll be facing a much greater uphill climb. And one thing to keep in mind is that with imaging there always seems to be another piece you need: a spacer here, an adapter there, different mounting hardware, a different cable, etc. That all adds up pretty fast. But With $3,000 you could build a beginning imaging kit and add to it later. A better budget would be $5,000, which would open up your options considerably. Even then, you will find there’s always more to buy to improve your imaging system. And this is one reason I really advise people to steer clear of imaging until you know a bit more about telescopes and astronomy and are sure you want to deal with the cost and frustration involved. There WILL be frustration, I promise you that.


Smart Telescopes

There’s a fairly new kid on the block when it comes to astronomy and imaging. These are generally classified as “smart telescopes,” and the market is growing. They are generally all-in-one instruments that combine a telescope, mount, and camera system You don’t observe through an eyepiece (there is one exception… sort of, and I’ll come to that). They all use a technique known as live stacking to quickly produce an image that is refined as long as you’re still on the object. In most cases they’re controlled via a wifi or bluetooth connection and an app or webpage on your phone or tablet.

With most of these, you set the instrument down on the ground or a table, probably unfold the legs of the tripod, perhaps remove a lens cover, and turn it on. It will go through its own alignment process, though you may have to guide it a bit through the interface, and then it will be ready. You select what you want to look at, and it will slew the scope to the right orientation and start the imaging process. In most cases, you can save the images for later viewing, or you can just view them while they’re on the screen.

Behind the scenes, what’s going on is this: The system captures an exposure, typically not a very long exposure, sometimes a few seconds, perhaps as much as 15 or 30 seconds, or perhaps fractions of a second (for things like the moon and planets). It then adds the image to a queue in memory. It then utilizes a process known as stacking to produce a better image. This is a complex process, but essentially amounts to a statistical analysis of each pixel in each image to produce the best image it can. Every individual exposure that’s added is used to better refine the image, so over time it will get better and better, showing more detail and reducing noise. This is the same basic technique used by astrophotographers of all sorts, though somewhat simplified and sped-up.

You will need to do a little adjusting through the app, maybe playing with brightness and contrast, but you’ll start to get an image fairly quickly and it will just get better the longer you keep the telescope pointing at the target.

Sounds great, right?

I have mixed feelings about these, and really don’t recommend them to beginners. First, you don’t learn much. You tap a few buttons and sit back and look. But you’re mostly just a passive observer. For a lot of people, this can get boring rather quickly. This is particularly the case when you don’t know all that much about what’s up there and are just scrolling through a list of things to look at. I’d guess that the majority of people using these look at the same handful of objects over and over, occasionally finding something new, but mostly sticking to what they know… and that gets boring fast.

Second, as with any complex computerized system, if something stops working, there’s no backup option. If you run out of power, game over. And I suspect if something breaks, the cost of repairs is probably very high.

Here’s the part that really bugs me: you’re looking at pictures, not the real thing. When you look through an eyepiece at the Andromeda Galaxy, photons of light are entering your eye that have traveled roughly 2.5 million light years to reach your eye. Think about that for a moment: you’re actually interacting with something that has traveled that long and that far to end up causing a chemical reaction in your rod and/or cone cells of your eye to stimulate your brain to form an image. The ACTUAL photons from that object are reaching your eye. Think about that for a second.

With a smart telescope, or any imaging system, you’re looking at a digital representation of the light, but not the light itself. Yes, you will see more detail, but, at least to me, there’s something very detached about it. And, since you’re just looking at pictures, when it comes down to it it’s not much different than doing a google search and finding images of the object taken by the Hubble Space Telescope or other telescopes and observatories. It’s not like astrophotography where you’re capturing the raw data and processing it yourself. You’re a passenger, not a pilot.

I’m not saying these don’t have a place in amateur astronomy. For those people who take their equipment out to outreach star parties where groups or the public are invited to view things through the telescope, these are a bit of a game changer. But I don’t feel they replace the experience of actually observing through an eyepiece and communing with the cosmos. Maybe I’m an elitist jerk, but I really feel these take away a lot from the hobby.

With all that aside, if you really want one of these, the one I’d recommend is the new ZWO SeeStar S50. Zwo’s reputation for imaging equipment is excellent and the price on the SeeStar makes it very attractive indeed. For the past few years, they’ve been offering set of separate components – cameras, mounts, and a control system – that can provide a similar functionality, and it works fairly well. The SeeStar basically packages them all up with a user-friendly interface to make the SeeStar a fairly easy to use system which, from all I’ve seen so far, produces some pretty good images. The overall quality of some of the other options on the market might be better, but the price tags are mostly much higher.

I really don’t recommend any of these instruments, but if this is what you really want, then the SeeStar is probably the best option based on price and quality.


Final Notes

I know, this is a lot to digest. But if you’re going to spend the money on a telescope, there’s a lot to know, unless you’re willing to just toss some money out the window. I’ve seen a lot of people buy the wrong scope – either for themselves or for a present – and the user ends up disappointed and disillusioned, and the telescope ends up in the closet or garage, rarely, if ever, used.

I hope you have found this information helpful. I welcome comments.


TL;DR: Specific Recommendations

The following are general recommendations based on things like price and user:

For anyone

Under $500

Under $300

Under $200

    I really don’t recommend any telescopes in this price range, binoculars are usually a better option here

GoTo Telescope Systems

For Kids

For Younger Kids

I’ve been working on a spreadsheet with recommendations, prices, links, etc. This is probably going to be a work in progress for some time. Prices listed are subject to change, as is availability:

John’s Telescope Recommendations List

I really hope this has been helpful to anyone reading it. Good luck and clear skies!

Answering a Quora question about DSLRs for AP

 This is adapted from an answer I posted to a question on Quora.  The original poster had asked which would be better for astrophotography, a Canon D6 MkII or a Canon 90D.

Here’s my answer with a few minor edits.


Which one is better for astrophotography, 90D or 6D Mark II?

It depends on what kind of astrophotography you’re doing. Astrophotography isn’t just one thing, but a banner term for a lot of different types of imaging. And, as with any kind of photography, there’s no one-size-fits-all solution. Actually, with AP, specialized equipment is even more important. While a typical off-the-shelf consumer-level DSLR can be used for portrait photography, landscape photography, and most other kinds of photography, and do so competently (though not necessarily ideally), the same is not true for different kinds of AP.

I like to break things down into four key categories based on field of view and exposure:

Wide field is typically done with either a camera lens or short focal length telescope (essentially a camera lens IS a type of telescope, though with some specific features). Narrow field is nearly always going to be done with a telescope.

The field of view you get with a given lens or telescope depends on the focal length of the instrument along with the dimensions of the image sensor. Pixel count is not important to this, just physical measure of the image sensor. For example, a standard full-frame image sensor has a width of about 35–36 mm, while an APS-C sensor has a width of around 22–25mm. Connected to the same lens or telescope, the full-frame camera will have a wider field of view than the APS-C.

For example, if you were to use a Canon 200mm f/2.8 lens with the 90D, which is an APS-C sensor, you’d get a field of view about 3.7° wide b about 2.4° tall, while the 6D, which is a full-frame sensor, gives you a field nearly 6° by 4° with the same lens.

Narrow-field is pretty much always going to use a telescope, and the longer the focal length, the narrower the field of view. As demonstrated above, the sensor size is also important. For narrower-field, like planetary imaging, smaller sensors are generally a better option. If you were to buy a camera that’s specifically intended for planetary imaging, you will find most of those have very small sensors. For example, the size of the sensor for the ZWO ASI290MM is 5.6 mm by 3.2mm. If you were to use that with the same 200 mm Canon lens mentioned above, the field of view you’d get is only about 1° by 1/2° (actually, a little smaller).

If you want to capture an image of M31, the Andromeda Galaxy, which has an angular size about 3° wide, you need to make sure your camera and lens/telescope combination is capable of that field. On the other hand, if you use that same combination to try to capture an image of Jupiter, which at it’s maximum angular size is less than 1 arcminute in diameter (50.8 arcseconds, an arcsecond being 1/60th of an arcminute, which is 1/60th of a degree), then Jupiter would appear as a tiny dot on a large field of black nothingness. If you want to see an example, this link will show you an estimation of the view you’d get of M31 taken using a Canon 60Da and a 200mm f/2.8 lens: M31. Here’s the view you’d get of Jupiter using the same equipment: Jupiter. (Note: I’d originally done this with the 6D specs, but the image of Jupiter it showed was entirely blank).

Now, let’s say we exchange that lens for a telescope, say a common 8 inch f/10 Schmidt-Cassegrain like the venerable Celestron C8. Here’s the image you’d get of M31 with the DSLR: M31 in C8 with 60Da. Not a very good option for M31, but how about Jupiter: Jupiter in C8 with 60Da. Here, Jupiter is noticeably larger and you can start to make out the cloud bands. But still pretty tiny. What if we switched to the ZWO planetary imaging cam: Jupiter in C8 with ASI290. THIS is a good combination for Jupiter, or other planets.

When it comes to images that require long exposures, there’s some other considerations. For these images, the objects being captured are so faint that it requires we keep the camera shutter open for an extended period of time. While most conventional photography is done with shutter speeds measured in fractions of a second (daylight outdoor photography often uses a shutter speed of about 1/1000th of a second, indoors with good lighting, 1/125th of a second is pretty common, and most flash photography uses a shutter speed of 1/90th to 1/60th of a second), most deep sky (i.e. not the moon, planets, or other solar system bodies) imaging requires exposure times measured in minutes, even hours.

The problem here is that stuff up there moves, and while it may not seem to move rapidly to the naked eye, as you narrow the field of view, that changes pretty fast.

The Earth rotates 1 time in 24 hours. This means anything you see in the sky will complete a complete circle around the Earth in that time and end up in the same place as it was 24 hours before. Actually, because the Earth is also orbiting the sun, this isn’t quite right. Due to our orbit, the object will move a little more than 360 degrees in 24 hours. The difference is about 4 minutes, but we’ll ignore that for the purpose of simple estimation.

If you divide 360 degrees by 24 hours, you find that an object will complete 1/24th of a circle, or 15 degrees, in 1 hour. If we divide that by 60 minutes we find that the object will have moved 15 arcminutes in 1 minute, and further dividing by seconds shows us the object moves 15 arcseconds per second. This doesn’t seem like a lot, perhaps, but when you compare that distance to the field of view you get through your camera/lens/telescope combination.

Let’s look at that 90D. It has a resolution of 6,960 by 4,640 pixels. If we try shooting through that C8 I mentioned before, you find that the resolution of each pixel is about 0.32 arcseconds per pixel. If you are shooting a 1 second exposure, this means that the object will move almost 47 pixels from the time the shutter opens until it closes. If you have a star that’s 1 pixel in size, it will end up as a streak that’s 47 pixels long.

This is how you get star trail pictures: you set the camera up on a tripod, usually aimed toward the pole, and do an exposure of a few minutes. You end up with an image that shows the path the stars appear to take as the Earth rotates.

But most of us don’t want trails, we want pictures of galaxies, clusters, and nebulae, so this is a problem.

The fix for this problem is to use a type of telescope mount that “tracks” the sky as it moves. For this, you really need what we call an equatorial mount, which is aligned with the north or south pole (depending on which hemisphere you’re in) and provides motion that keeps the camera/telescope pointed in the same direction.

Mounts like this typically are not cheap. The cheapest ones that I’ve seen that could really be recommended for AP start in the neighborhood of about $500, and that can only handle the camera and a very small telescope or relatively small lens (I’d say no more than 300 mm focal length, if that). As the field of view decreases in size, the weight of the camera and lens/telescope payload increases, or the exposure time increases, the demands on the mount increase, requiring more and more accurate and capable mounts. Of course, this means the price tends to increase rapidly as well.

Exposure time is a major part of this. The longer the exposure time you need, the more accurate and precise the mount needs to be. So one way we can reduce the demand on the mount is to decrease exposure time. We’re still going to be talking about minutes, usually, but we can still make it easier on ourselves.

When you get down to it, the image sensor is essentially counting photons. As a photon of light reaches the photosensitive material of the image sensor, it increases the charge on the semiconductor material a tiny amount. When the exposure completes, the electronic brain on the sensor counts up how much charge each pixel has and converts that to a data set that describes the light the sensor encountered. Most digital cameras these days use CMOS sensors, which are 14-bit image sensors. 14 bits allows for a numeric value between 0 and 16,383. In this case 0 would be black and 16,383 would be white, and any value in between is a shade of gray (let’s ignore color for the time being, though it works the same way). When you capture the image, the image file basically will contain a value between 0 and 16,383 for each pixel, which the computer can then reconstruct into an image.


Ok, quick explanation of color: the image sensor is only sensitive to light, not to specific color. The sensor is counting photons, essentially, and doesn’t give a rat’s rear-end what color they are. So to get a color image, we filter the light. If you place a red light filter over the sensor, you’ll only be counting photons of red light. To capture a color image, we then need the red, green, and blue light to mix together. The way a color image sensor does this (what we refer to as a one-shot-color or OSC sensor) is to have a grid of pixel-sized filters mounted over the pixels of the sensor. This is called a Bayer pattern. In most cameras you end up treating every 2×2 group of pixels as a single unit here and of these four, there is usually one red, two green, and one blue filter over the pixels. So when the light comes in, one of the pixels is only seeing red, two only green, and one only blue. These values are then mixed together to create color. These 4 pixels aren’t actually treated as a single pixel, but the adjacent color values are combined or blended with the native color of the given pixel to assume the color for that individual pixel. They are then saved into the image with three 14-bit values per pixel, which means the uncompressed raw image file will be about 3 times larger. But discussing the nature of these files is a topic for another time..

Ok, so let’s say you have a camera mounted to a telescope and take a picture. Let’s just throw out some hypotheticals here and say the telescope has a focal length of 500 millimeters and an aperture of 100 mm. This gives it a focal ratio of f/4(as the focal length is five times longer than the aperture diameter). Let’s say now that you’re capturing an image of an object that’s roughly circular in size. With your image sensor, whatever camera you’re using, the image covers a spot on the sensor that’s roughly 100 pixels wide. If you do the math to solve for area, you’ll find that this means it covers a total of about 7,854 pixels. Now, let’s imagine that you do a 1 minute exposure and in that time, the average pixel captures about 2000 photons worth of light. If you add it all up, this means a total of about 15,708,000 photons were captured.


Now, let’s say you change to a telescope with a focal length of 1,000 mm, twice as long, but the same aperture. Your focal ratio is now f/10. You try to do another 1-minute exposure with the same camera. The doubled focal length means the field of view is cut in half (which makes it appear that you’ve doubled magnification). Instead of covering a spot 100 pixels wide, the object covers a spot 200 pixels wide. If we solve for area, we now find that the area of the spot is 31,416 pixels (when you double the diameter of a circle, you square the area).

Now here’s where things become problematic: the amount of light received is dependent upon the aperture of the telescope, not the focal length. If you have two telescopes of the same aperture regardless of focal length, the number of photons each will collect will be the same (well, of course, it’s not going to be 100% the same, but close enough for our purposes), so a total of about 15,708,000 photons were captured, but now they’re spread over 31,416 pixels, for an average of about 500 photons per pixel. The image is 1/4 as bright. It’s larger, but it’s much fainter. To get the same level of exposure, you need to increase exposure time by a factor of 4 – 4 minutes to get what the shorter scope got in 1. While we have to use long exposures to capture the light we need, we have to balance that with the abilities of our camera, mount, and lens or telescope. The longer the exposure time, the more likely we are to run into problems, whether that be with small errors in our mount’s tracking or guiding, minor errors in alignment, or something like an airplane, satellite, or shooting star passing through the field of view during the exposure.

This is why astrophotographers tend to prefer telescopes and lenses with shorter focal ratios. We refer to a shorter focal ratio as a “fast scope” for just this reason.

And this is where another issue comes into play: pixel size.

The pixels on the 6D MkII are about 5.67µ in size (that’s 0.00567 mm). Those on the 90D are 3.2µ in size (0.0032µ). Those on the 6D Mk II then have 0.032µ^2 of surface area while the 90D have only 0.01µ^2. More surface area means more light collected. In this case, the pixels of the 6D MkII are exposed to more than 3 times as much light as the 90D. All other factors being equal, the 6D MkII would capture in one minute the same level of brightness the 90D would capture in over 3 minutes.

But then, not all image sensors are equally sensitive. I can’t find the statistics on the 90D, but the 6D MkII has a peak Quantum Efficiency (Qe) of about 52%. This means that roughly 52% of the photons of light that reach the sensor are detected. I don’t know what the 90D’s Qe is and can’t find it. It might be higher. But that has to be balanced against the size of the pixels. If the sensor’s Qe is 60%, the 6D Mk II would still capture light more rapidly due to the larger pixels.

You must also consider the issues with sensor noise. Astrophotography is actually more a game of signal processing than conventional photography. With AP, we are concerned with signal to noise ratio, while for conventional photography, the sensor noise is usually too minor to notice in comparison to the well-lit subject and background. With AP, the target is usually very faint and we are trying hard to boost the SNR to produce a good image.

And here’s another issue to consider: sensor size versus lens/telescope light spot. This is less an issue for camera lenses: if you get a lens that’s intended to be used with a given camera, this shouldn’t be a problem. But when dealing with telescopes, you have to take into account the diameter of the light cone at the point of focus. Most telescopes, even those intended for astrophotography, will not provide full illumination to a full-frame sensor such as that in the 6D MkII. Most of these WILL work with an APS-C sensor, but not all. If you’re imaging through a telescope, this is an important consideration.

Another problem you’ll run into is that  nearly all conventional digital cameras are produced with a built-in filter. This filter is typically installed directly over the image sensor and does two things. First, and least important, it helps protect the sensor from dust, moisture, etc…. This is a secondary function, but still somewhat important. The big issue for AP is that this sensor is designed to limit longer-wavelength light.

In the electromagnetic spectrum, light toward the blue-end of the spectrum has a shorter wavelength (about 400nm) than light at the red-end (about 700nm). While (most of us) obviously can see the color red, as it turns out our eyes are really not well-suited to it. If your eyes were equally sensitive to all wavelengths of visible light, everything would seem a lot pinker. Digital cameras don’t have this problem, and often their peak Qe is closer to red than green or blue. As such, if you do not adjust the color balance, an image taken with a digital camera will seem very red-tinted.

To aid in the color balancing, the filter over the image sensor is designed to reduce the amount of red light reaching the sensor. I’ve heard various amounts, but it’s somewhere around 2/3 to 90% or more of longer-wavelength light.

And for AP, this is a big issue, because there’s a lot of interesting stuff at longer wavelengths. In particular, this:

(Shamelessly taken from Wikipedia)

This is an object known as NGC2244 (actually it’s cataloged under NGC2237, NGC2238, NGC2239, NGC2244, and NGC2246… as different parts were originally believed to be different objects) , or Caldwell 49 (for the nebula) and Caldwell 50 (for the star cluster), and is probably best known as the Rosette Nebula. A lot of the nebulosity in this image is from light with a wavelength of about 656.28nm. We refer to this as Hydrogen Alpha and it is produced when the electron in an atom of hydrogen falls from it’s second-highest to its third-highest energy state. When that happens, a photon of light with a wavelength of 656.28 nm is emitted.

But there’s a problem: that filter I spoke of will block somewhere between 2/3 and 90% of the photons at this wavelength. This means that to capture an image of this object, or many astronomical objects with a lot of red in them, you need even longer exposures still… and/or a lot of exposures.

For a couple decades now, astrophotographers have modified DSLR cameras to remove this filter or replace it with one that doesn’t block red light. But doing this is problematic. Digital cameras are not designed to be modified or repaired by the user. They have lots of intricate and very sensitive parts, and it’s really easy to ruin the camera this way if you don’t know what you’re doing. It also will violate any warranty you might have.

In 2005, in response to this need, Canon released the 20Da, which was a pre-modified version of their 20D. They replaced the sensor with one more transparent to red, and made a few other modifications, primarily in firmware. In 2012, they did it again, releasing the 60Da, a pre-modified 60D. This was not only a few generations newer camera (with a better, higher resolution sensor), but also had a better filter to allow red-light passage and more firmware upgrades for AP use. Nikon, which has not been anywhere near as friendly to the AP community as has Canon, finally jumped on the bandwagon in 2015 with the D810A. A generation or two newer than the 60Da and using a full-frame sensor, it was superior to the 60Da, but also a lot more expensive. It also has a full-frame sensor while the 60Da and 20Da had APS-C sensors. About a year or so ago, Canon did it again and released the EOS Ra, which is an adaptation of the EOS R mirrorless camera.

The problem then with these, however, is that without the standard red filter, images look very red-tinted. You can partly fix this through the use of a white-balance profile, which will mathematically modify the image to balance out the colors. This is usually ok for casual use, but experts and professionals aren’t usually satisfied by it. You can also purchase clip-in filters that go inside the camera body when you detach the lens, and then the lens clicks on over it. But this is and additional cost and you need the right filter for the right camera.

Of course, casual astrophotographers may try to use a stock camera without modification. And I’ve seen good images done this way, but not as good as those done with modified sensors. And even then, better images still are captured by cameras that are designed for astronomical imaging, such as those made by the Santa Barbara Instruments Group (SBIG, which is a part of Diffraction Limited), Finger Lakes Instruments (FLI), and ZWO out of China. These cameras are designed specifically for AP. Many of them are monochrome and can be used with filter wheels, which allow for even better imaging results in the right hands. Unfortunately, they’re not cheap and not multipurpose – they’re designed for astronomy only.

If you want to do AP, you’re probably better off not getting either camera. The best option I can recommend is to find a used and pre-modified Canon DSLR. Sites like the classified ads on Cloudy Nights and Astromart often have them for sale. An older model that’s pre-modified can usually be found for a few hundred dollars, often professionally modified by services that specialize in doing so (I believe a few have manufacturer-certified technicians that can do the mods without voiding the warranty… but you’d have to check to be sure). They also often come with the interface cables needed for computer control (which is extremely important for long-exposure imaging) and and power adapters to plug into standard a/c power or a 12v power source.

I also would STRONGLY recommend joining a local astronomical club or society in your area. Nearly every major and many smaller cities in the US, Canada, and Europe has one, and most such organizations have a least a few people doing AP already. Join up, find those people, and learn from them. AP is not an easy game to play.

Good luck and clear skies!

Getting (re-) started

(This was originally posted on my blogger blog)

I spend a fair chunk of time writing answers to questions on Quora.com and reddit.com/r/telescopes.  I’m thinking of moving some of those answers here to provide a handy reference.

If you have any astronomy-related questions, please feel free to ask.

Resurrecting my blog… again.

I’ll be honest. I suck as a blogger. I’m inconsistent at best, negligent at worst. However, I’ve been trying.

A few months ago, I started blogging on Blogger.com (you can find that blog here). Unfortunately, blogger doesn’t allow me to post Amazon ads in my blog. Which, if you ask me, is total bs, particularly since I tried to sign up for an AdSense account and they denied me.

So, I’m now moving my blog here… I guess… for now, at least. The next few posts will be copied content.

Anyway, I’m trying to blog more. If you’re there, reading, please feel free to kick my butt and tell me to blog more – that is, assuming you like my content.

Welcome to the world of 3D printing!

I’ve been planning to do this for a while, and finally did it. I purchased a 3D printer.

I spent hours agonizing over what to get. I didn’t want to spend too much, not knowing how useful it would be, but didn’t want to get low quality either. I finally landed on a Creality Ender 3.

It took a couple hours to assemble, but now I’m printing stuff. I still have some bugs to iron out, a few adjustments to make and things to print to make the printer work even better (things like belt tensioners and the like). But it’s already turning out some usable stuff.

A few days ago I printed a cap for one of my DSI cameras. This was a design I found online, and it fit just fine. I’m somewhat amazed by the ability to PRINT the threads, especially fairly fine ones. But it’s working just fine.

Last night, before bed, I started the print on my first self-designed usable astronomy tool. I have a 50mm finder that came with my 8″ SCT, but really has never been useful. The diagonal on the finder was cracked and never stayed on right. But I always thought it would be a good guide scope, if only I could adapt it for a camera.

So I’ve designed an adapter that screws on the back and offers a simple helical-style focuser for focus adjustment. At 100 microns detail resolution (to get the threads just right) it calculated out to a 12 hour print. It was over halfway there when I woke up this morning, and looking good. By the time I get home tonight it should be entirely complete… then I can assemble and test.

I also want to print a DSLR lens adapter for my CCD’s to allow wide-field imaging. That should be my next design.

After that? The sky’s the limit!