For amateurs starting out in astronomy, choosing a first telescope is exciting. Choosing telescopes for beginners can even be daunting. Several jump to Cloudy Nights and start a thread with the title “Which telescope should I buy” or even “Which is the best telescope?”. Cloudy Nights is a treasure. It’s got so many experienced astronomers offering advice for free. However it is difficult to address the myriad nuances to telescope purchases in a single forum thread. By all means post your own question there, but I think it helps to first familiarize yourself with this subject, so you can ask specific questions on the forum and increase the odds of getting good answers that address your particular needs. This is why I wrote this article.
Although the usual telescope recommendation for beginners is a Dobsonian, and let me say right here that in most cases it is what they should get, it might not be right choice for everyone. Each telescope has a certain light gathering power, field of view, cost, quality, size and weight, carrying capacity, support from the manufacturer, and maintenance requirements. All that makes a telescope suitable to a greater or lesser degree to different targets in the night sky. Add to this the rational or irrational preferences and desires of human beings, and its clear that no single design will make everyone happy. This article aims to help beginners choose their first telescope. I’ve drawn on first-hand experience with several telescopes as well as the opinions and experience of others in the community. The intended audience is people who are seriously interested in astronomy and want to get started or have just gotten started. There is a lot of ground to cover. Let’s get started.
Required reading
I’ll assume you know the basics already. If you don’t, I suggest you first read this article by Sky & Telescope and this article by Ed Ting. I’ll assume you know the basic designs, viz. reflectors, refractors, and catadioptrics and that you know the difference between the telescope tube, diagonal (if applicable), the eyepiece, the mount and the tripod. For most of this article, when I refer to “telescope”, I really mean the whole system including the mount. While not required reading, this article by Al Nagler is also informative.
Some background about myself
I began with the PowerSeeker 127 EQ back in 2007. Later, I bought a few ED refractors, and finally a few “big” SCTs. Along the way I bought and sold a few different mounts, several dozen eyepieces, and a handful of diagonals and filters. At star parties I have looked through an 8″ Dobsonian, a 13″ home-made Dobsonian, a 16″ Ritchey-Chretien, a TeleVue 85mm and 100mm APO, TeleVue 127 IS, a few Celestron and Meade SCTs, an Orion ShortTube 80, and perhaps a few others I can’t recall.
- Celestron PowerSeeker 127EQ (a mediocre reflector, now donated)
- Sky-Watcher ProED 120mm (an excellent 4.7″ ED refractor)
- StellarVue SV110ED (a discontinued, very good 4.3″ ED refractor, now sold)
- StellarVue SV60EDS (a very small, excellent 60mm refractor)
- Celestron C8 XLT (a sizeable, very good 8″ SCT, now given away)
- Celestron C9.25 XLT (a massive, excellent 9.25″ SCT, now reluctantly sold)
- StellarVue SVR90T (an excellent apochromatic 90mm refractor)
- TeleVue Ranger (a small and light, discontinued, usable 70mm ~ED refractor, now sold)
- Vixen VMC110L (a modified Cassegrain, a very disappointing telescope, now sold)
Pre-requisites for beginners
Before buying a telescope, you should have:
- Some knowledge about the night sky.
- Some time spent under the night sky.
- Realistic expectations (don’t expect Hubble images).
In the grey area between pre-requisite and nice-to-have is the experience of looking through someone else’s telescope before you buy yours. No amount of internet research is a substitute for actually looking through one, and each design has a different character to the view. Try to seek out a local astronomy club or library that can lend you a beginner telescope or find public outreach events. Looking through a telescope first, and seeing what the owner had to haul and how long it took them to set it up, will also help you decide if you really want to own one or is this just a fantasy.
Another thing you could do is go to an astronomy expo, like the annual NEAF expo in NY state. Other than the fact that you could get some incredible deals here, you really get to see what is on the market. I’d highly recommend going to it. There’s a similar astrophotography expo that happens on the west coast, but I don’t know what it is called. It’s probably just as great.
Start with knowledge
Start with familiarizing yourself with the night sky, at least to a little extent. That means being able to recognize major constellations, and the bright stars in those constellations, and how those constellations will change over a year.
Stellarium is a free night sky simulator. It will even simulate the view of various night sky objects through telescopes and eyepieces, though you’ll have to enter specific telescope and eyepiece parameters to get an accurate simulation.
What Stellarium won’t do is to introduce you to astronomy. Stellarium is a map. What you need is for someone to show you the way. A guide that takes you on a path through the forest pointing out interesting things along the way. This is where a book comes in. It is much cheaper than a telescope. It’s also a lot smaller than a telescope. It will also give you a taste of the practicalities of operating a telescope. I recommend the book Turn Left at Orion. It includes hand-drawn illustrations of what different objects like planets, star clusters, galaxies, and nebulae look like through a small telescope.
Contrary to popular advice, I do not consider binoculars a good starter instrument for astronomy. While binoculars reveal several more stars than the naked eye, and a few chosen targets look exceedingly good in binoculars, most everything in the night sky is too small to detect, let alone appreciate, with binoculars even at 20x. And good binoculars cost money, sometimes nearly as much money as a telescope. Low power binoculars are, however, useful to navigate the sky alongside a telescope, especially when using manual mounts. [TODO] See my binoculars article here.
Setting the right expectations with beginner telescopes
When some of my friends looked at Jupiter at 200x through my ED refractor, they asked me with an air of disappointment “that’s it?“. I guess they were imagining detailed Hubble images of Jupiter. Jupiter through a telescope doesn’t look anything like the images on the internet. Sure it is impressive to see the planet as a bright small, if not tiny, disk, with at least 2 contrasty bands at the equator, and the 4 Galilean moons as bright points of light around it, but that’s a whole other thing compared to what Hubble will show you.
Another limitation of Stellarium is simulating optical quality. Jupiter will look different in a $200 80mm achromatic refractor than in a $2500 4″ apochromatic refractor, and likewise different in a $40 eyepiece than in a $500 eyepiece. The difference will be in how sharp and contrasty the view is, the presence or absence of purple halos around the edges of the planet, the shape of stars in the center and also towards the edges, etc. There’s a reason why those telescopes and eyepieces cost as much, and not all of it has to do with R&D or brand-name premiums. Cost alone is not a good indicator either. E.g. A $1500 12″ Dobsonian will blow away that same $2500 4″ APO when viewing globular clusters.
Another thing to keep in mind is that deep sky targets (galaxies, nebulae) other than the brightest ones pretty much require dark skies. That means going away from a city, and preferably to some place with high altitude, or atleast waiting for the new moon in suburban skies. The moon and planets on the other hand can be seen well in a telescope from anywhere, even from a lit sidewalk in a city.
And don’t look at the sun, even accidentally, through a telescope.
Considerations when choosing a first telescope
The two biggest factors that impact your experience are:
- How much can you afford
- What size, weight, and assembly you can realistically manage
The second is much more important than the first. A Dobsonian (or any reflector) needs frequent collimation. This might not appeal to everyone, indeed it might frustrate some. If your telescope is so big and heavy that you just don’t feel like taking out of storage to use it, that telescope was better not bought in the first place. Get a telescope that you will use regularly, even if that means getting a small one. More aperture is always better, but can you really get a lot of use out of a 14″ Dobsonian?
Aperture envy is a fatal disease. Don’t feel guilty or insignificant because you don’t own the biggest scope in your timezone. Any telescope makes poking around the sky a lot more fun.
The Dobsonian Telescope – David Kriege and Richard Berry
It’s also important to correctly estimate what you can comfortably spend on the hobby. E.g. If you can really afford $2000 but your desire to economize drives you to only spend $500, what could happen is that you’ll initially spend $500, be disappointed with what you bought, then sell and upgrade it to a $1000 scope at a loss and hassle, but you’re still not satisfied so you sell that and finally get the $2000 scope, and by this point you’ve spent over $3000 and have lost precious time. You could have gone for the $2000 scope right away. Buying can be trivial, and selling can be a nightmare.
GoTo mounts
If you can afford it, and you know you’ll be in the hobby for a long time, just get a GoTo mount from the outset. Before you moan “Oh but it won’t teach you to star hop and learn the night sky”, let me explain.
Consider the scenario of observing Jupiter at 225x through a 60 degree apparent FOV eyepiece. At this magnification and field of view, it will take about 1 minute for Jupiter to cross the entire field of view of the eyepiece (things are moving in the sky remember?). That means you need to keep turning the telescope very slightly every now and then with the slow-motion controls so that the planet remains within the field of view of the eyepiece. However every time you even touch the mount, it makes the view wobble for a few seconds. The higher the magnification, the more the wobbling effect. So you need to wait a few seconds for the vibrations to die down until you get a steady view, but then soon you’re going to move it again. The result is that you don’t get extended steady views of the planet. The atmosphere isn’t always co-operative either. Several times it so happens that the turbulent air makes the view shimmer, like a mirage. Only for a few fleeting seconds do those currents disappear yielding an absolutely stunning view with subtle details clearly visible. You don’t want to be messing around with a manual mount while all this is happening.
Good GoTo mounts give you extended steady views, allowing you to see subtle detail more easily, and also make it easier to share your telescope with others. They also make finding objects easier (if you’ve calibrated them properly). Yes they make you lazy and you probably won’t develop star hopping skills, but personally I find that ok. GoTo is not 100% accurate anyway, and when its not you will need to starhop manually. However the GoTo convenience comes at a substantial cost. So don’t worry too much if you cannot afford the GoTo, you can always dial down the magnification with a different eyepiece to make manual tracking easier.
Buying a telescope for children
If you’re buying a telescope for a child and are ready to do some adult supervision, then a solid tube a.k.a. classic Dobsonian makes a lot of sense. It’s relatively inexpensive, easy to operate, and provides views of the moon and a few planets that will amaze the child (and probably you too).
The downside, however, is that Dobsonians need frequent collimation to ensure you’re getting the best possible views through them. The most common sizes for beginners are 6″, 8″, and 10″. If you must get a Dobsonian, then I agree with Jon Isaacs over on Cloudy Nights that you might as well get the 10″ instead of an 8″ (similar telescope bulk and weight but much better views in the 10″), keeping in mind that the f/4.7 ratio on the 10″ does make it a more sensitive instrument compared to the f/6 on the 8″. A Sky-Watcher or Orion solid tube 10″ f/4.7 is a very decent option even for adults, and so are the 6″ f/8 and 8″ f/6 Dobs. From this point on, I will call these the starter Dobsonians.
Make sure that you or your child never point the telescope to the sun, it WILL cause permanent blindness.
Observing deep sky objects
To do any serious deep sky observing (i.e. globular clusters, galaxies, etc.) you will need one big good quality telescope. I’ll define big as 8″ to 10″ in aperture. Yes, I know the Dob guys are laughing, an 8″ Dob is considered small enough to be a grab-and-go telescope compared to the 14″ and 16″ Dobs. Regardless, we’re talking about beginners here.
Dobsonian telescopes
Dobs can get big really fast. A 6″ and 8″ Dobsonians are not that big, even a 10″. Take a look at the two pictures below from NEAF in 2018. I’m 5′ 8″ for reference.
A solid tube Dobsonian <= 10″ is less bulky than an equivalent SCT because the SCT also needs a hefty mount and tripod to make it work. If you want to start observing as quickly as possible from the moment you take the telescope out of storage, a Dob wins over an SCT. Cooling time is near identical for Dobs and SCTs. You’ll most likely need to collimate it though. Take a look at the video below.
12″, 14″ and 16″ are considerably larger and heavier than a 6″.
SCTs
I have much more experience with SCTs than with Dobs. There’s a noticeable difference in views between an 8″ and 9.25″ SCT. However the 9.25″ SCT is a beast by comparison. You will need either an older heavier mount (like the Orion Sirius or Celestron CGEM which weigh around 40 lb for the mount alone, not the tripod!) or one of the newer and lighter but quite expensive iOptron ones. If you can lift a big 25lb bucket up to a height of about 5′ 6″ (that’s about as high as the CGEM DX mounting plate), go for it! Otherwise stick to an 8″ SCT to start with, because you can get away with an AVX mount for that. There are horror stories of telescopes crashing down or banging against the tripod because the counterweights were removed first! Also this combination is considerably more expensive than a GoTo Dob of the same size, and it might overwhelm you if you’re not very technically inclined.
Dobs and SCTs compared to a refractor
Compared to ED or APO refractors though, I found stars were not as pinpointy, however I’m not ruling out bad collimation, poor seeing (that is an atmospheric term) or a poor quality focuser.
One other thing is that there is a notion floating around that to see planets, a refractor is the best instrument, so-called “planet killers”. For the record, my C9.25 showed better views of Jupiter and Saturn than my 90mm StellarVue APO ever did, and the APO is no slouch. So take the hype around refractors with a big grain of salt. Refractors win on size and if it’s an ED or APO then pinpoint stars and overall sharpness / contrast in the view. But their smaller size is also their biggest weakness. Like most things there’s a tradeoff.
Which one to get?
The choice between a Dob and SCT may not boil down to a rational criteria like size, weight or cost. Personal preferences matter a great deal and is normal. This is why it’s important to look through some telescopes before buying one. Choose a telescope that makes you happy.
Observing the moon and planets
Focal length matters!
To see planets well, you need high magnification. Around 150-180x is where Jupiter and Saturn start to get interesting. It gets difficult to achieve these high magnifications with a telescope that has a very short focal length. Getting high magnification with any modern refractor telescope relies on using short focal length eyepieces or using a barlow. I consider 560mm the bare minimum to reach the high magnifications stated before. E.g. a 3.5mm eyepiece yields 160x with a AT80ED f/7 telescope (with 560mm focal length).
Why get a refractor?
You might not have room to store a Dobsonian or a big SCT with a big mount. Perhaps you find a Dobsonian too big to use often, or you don’t like the hassle of collimation, or you’re thinking of transporting your telescope to a dark sky location by airplane. Perhaps you only want to look at the moon and 4 bright planets.
If this is you, a refractor might suit you well. ED refractors between 80mm and 125mm are, in my mind, the sweet spot for price and performance. Smaller than 80mm gets challenging for a beginner. With an ED or APO refractor, you get high contrast views right off the bat and they are pretty much grab-and-go instruments. Well, almost. To get the best views from any telescope, it first needs to reach thermal equilibrium with the outdoors ambient air, so you do need to account for that time. The bigger the scope, the more “cool down” time it needs. “Seeing” matters as much, as mentioned above, however since refractors are generally smaller than SCTs/Dobs, seeing probably affects them to a lesser extent.
Refractor telescope expectations
Note that deep sky objects like globular clusters, planetary nebulae and galaxies are nowhere as impressive in any refractor compared to a big scope regardless of what the refractor advertisements say. E.g. it takes an 8″ scope to detect the hole in the Ring Nebula well. However if you limit your viewing to open clusters, the moon and planets, and some of the other bright showpiece objects, you’ll be happy with a refractor as your sole instrument. In fact for the moon and planets, you don’t even need to be in a dark sky location, you can see these from a brightly lit sidewalk.
Refractor optics
I’d strongly advise against getting an achromat. Personally I find purple / yellow halos around bright objects very unpleasant. Some people find them tolerable. I’d argue to save up enough money to at least afford an AT80ED. In the long run, that extra $200 (compared to the $199 Orion ShortTube 80 achromat) won’t matter so much, but the fact that you got rewarding fringe-free (and consequently crisper) views of the moon and planets will.
Small refractors for daytime use
While I consider 60mm too small for astronomy, it can double-duty as a daytime spotting scope with an erecting prism instead of a star diagonal. Below is a StellarVue 60mm SV60EDS being used for birdwatching. This model is now discontinued, but other brands offer similar models today. Among the priciest of these are ones made by TeleVue and Takahashi. Again, I would not recommend these as first telescopes.
Don’t get me wrong, you can do some astronomy with a 60mm telescope but the maximum usable magnification for a bright planet like Jupiter with this scope is around 45x, any higher and the views get too dim. 45x, while cool, is not quite enough to generate excitement about the planet (just my opinion), and while you can push the magnification in this scope to about 90x or even 110x, by then the views are so dim that they are disappointing and you need a solid (big and heavy) GoTo mount to achieve very high magnifications with a scope this small, which beats the point of portability. A 60mm scope is great for traveling though and nothing beats it for grab-and-go. I can lift the tripod, mount and scope with one hand 🙂
Another thing you can do with a scope like this is project the sun onto a paper to look at sunspots!
Again, make sure you don’t look at the sun even accidentally through a telescope, you will lose your eyesight.
Brands
Dobs and SCTs
Sky-Watcher, Orion and Celestron are good reliable brands are my top 3 for value for money. GSO is probably also good though I have neither owned nor seen through one of their scopes, and I feel the same about Astro-Tech (owned by Astronomics). I don’t have experience with Explore Scientific, I stay away from this brand having seen their marketing and product offerings, however I am open to changing my mind. Speaking of brands, atleast some Western brand names are in the business of rebranding Chinese made telescopes. I’d encourage you to be open minded and try out various brands yourself. There are also smaller companies that make very high quality Dobs in limited quantity with wait lists, but those I think are not suited for beginners, they are more like Rolexes than Toyotas.
Refractors
If you want a refractor, my first choice would be the Sky-Watcher ProED / EvoStar series for their value for money, followed by the ED or APO scopes by Astro-Tech. TeleVue, StellarVue and Takahashi are great if you can afford them. Do have a look on the used market as there are very good deals to be had. StellarVue no longer makes ED scopes, but you can look for their discontinued ED models on the used market. Nowadays they only make APOs and these do not provide good value for money for visual astronomy (way too expensive).
Foreign sellers
If you’re feeling adventurous, have a look at some of the SharpStar and SVBONY ED refractors being sold on AliExpress. I have no personal experience with these but they look like they might perform alright. Note that if you encounter any QA issues with such a delivery from China you’re probably going to be stuck with a lemon. I don’t know what their support model is. In Europe, there’s APM and Teleskop Service, both of which I have never used personally, however their scopes’ specifications look alright, they have been at NEAF before so it is possible they have a dealer in the USA.
Mounts
The down side with refractors and SCTs is that you will need to buy the mount separately and ensure they are compatible. The MacroStar or UniStar Deluxe Alt-Az mounts from Universal Astronomics (which is now out of business) are good sturdy manual mounts. There are good options from iOptron and Sky-Watcher (my two preferred choices) in the $900-$2000 range. Celestron AVX is a good choice as well. Bear in mind that the carrying capacity on mounts is often overstated, and if you’re interested in astrophotography, the rule of thumb is to consider the real carrying capacity of the mount as half the rated capacity.
Eyepieces
Eyepieces deserve their own article. My personal favorites are the TeleVue DeLites. I see eyepieces as more or less forever items. Unless you abuse an eyepiece it will last you a very long time, so I tend to go only for the high-end eyepieces nowadays. They also retain their value well on the used market. However if you are constrained by a budget, then again I’ll repeat something Jon Isaacs said on Cloudy Nights: you don’t want to compromise on the scope to set aside money for an eyepiece. It is easier to upgrade eyepieces when you have more money to spare in the future, it is not so easy to upgrade the scope. So if you must, limit yourself to cheaper eyepieces until you can afford the better ones. Check out AgenaAstro for some economical choices like the Starguider or BST series.
If you have deep pockets
I’d still suggest you to start with a modestly priced scope with the brands suggested above until you get enough experience of your own. After some experience you’ll have a much better idea of what you enjoy and what you don’t. If you must know, there are high-end brands like Takahashi, Obsession Telescopes, Teeter Telescopes, etc. that use premium grade optics. I have never seen through one of these but I would love to, and these brands have a loyal following. For mounts, there’s Losmandy and DiscMounts, although I’m not sure if these are suitable for a beginner. I have chatted with the owner of DiscMounts at NEAF and he seems very knowledgeable.
When and where to buy a telescope
Before COVID, there would be sales around Memorial Day, so this would be a good time to buy. If you live on the east coast of the US, consider going to NEAF which happens every year in April. It is a great way to see and handle many different telescopes. You get a sense of bulk and weight that you won’t get by looking at pictures online. There are also some discounts generally at NEAF (though very short lived). December is the other month when sales happen. With the supply chain disruptions of COVID, I’m not sure these are happening anymore.
Unless you are buying a starter Dobsonian, consider buying a used scope (my preferred option) from Astromart or CloudyNights as you can save a lot of money this way. I’ve bought and sold plenty of equipment in these forums. However CN being free also attracts more unscrupulous sellers in my opinion. Astromart has a $15 fee to join so it naturally cuts down on the scammers. If you buy from a reputable seller you’ll be fine, check feedback before buying. Do some research on how PayPal works if you want to buy used. Never use the Friends and Family option on PayPal to make payments.
Speaking of used gear, a couple of points:
- Mirrors (used in both Dobs and SCTs) lose their reflectivity over time, I wouldn’t buy a very old mirror. You can get mirrors recoated for a cost.
- Getting support for a used telescope is tricky. I have experience with StellarVue and TeleVue where I have had support for a telescope that I bought used, I called their office for help and both were very helpful. Ask around on the forums about what kind of experience people have had with trying to get their used scopes fixed if this concerns you.
If buying new, I’d suggest you to stick to stores that specialize in optics. I’ve had good experiences with Astronomics, B&H, OPT, AgenaAstro, Orion, HighPoint Scientific and buying directly off of StellarVue. Some of these sellers like Astronomics and HighPoint Scientific may even be able to advise you on your purchase. If instead you are buying from a big box store, check if they are offering the same configuration of the telescope compared to one being sold on one of the aforementioned ones e.g. is the focuser the same or different, which accessories are included, etc. These little things do matter.
Final thoughts
Buying your first telescope can be a daunting task. There are many things to consider and almost all choices will have tradeoffs. I would like to leave you with one final thought, which is that most serious amateurs have more than one scope, sometimes many! E.g. a big scope for deep sky, a small scope for grab and go, etc. You can approach your purchase with a goal of seeing some specific things well, and then later (or much later) get another scope to complement it. To get a decent and lasting experience from an instrument, I think the minimum money you need is around $350 USD (the price of a classic 6″ f/8 Dobsonian). Buy once, buy well and above all buy something you will use often.
How much do telescopes cost?
It depends. Entry-level decent telescopes cost around $300 USD. Enthusiast level telescopes can cost many thousands of dollars.