Astrophotography is an extremely dedicated hobby, one that requires significant financial and time investment to do right. In this article, we’ll mostly be covering deep-sky astrophotography, which is what the vast majority of amateurs are interested in.
When I talk about astrophotography, I am referring to photographing deep sky objects (DSO’s) – namely galaxies and nebula. Planetary photography requires different considerations. If you want to just shoot the Moon and planets, we recommend reading our Best Planetary Telescopes article and connecting a CMOS planetary imaging camera to whatever you buy – that’s all you need.
If you don’t want to read the whole guide, below is a list of 5 best telescopes for you to use in astrophotography. Take a look and see which one you’d like to be your personal companion as you discover and map the wonders of the universe.
Before going deep into our telescope recommendations, let’s discuss some basics of deep-sky astrophotography. Deep-sky astrophotography is different from visual astronomy in a number of ways. Here are some big ones.
1: Astrophotography is a la carte
When shopping for an entry-level telescope for visual astronomy (i.e. looking through the eyepiece), you are generally buying a single product which you can at least get by with no additional purchases besides maybe a couple of eyepieces. Not so with astrophotography.
Deep-sky astrophotography, at a minimum, requires a telescope optical tube assembly (the part that actually gathers and focuses light), a precise computerized equatorial mount, and of course a camera. You really should also invest in a guide scope, autoguider, and a quality laptop to control your whole setup with – the former two are things we’ll cover in this review along with the Big Three components.
2: Astrophotography isn’t necessarily all about larger aperture the way visual astronomy is
The vast majority of beginning astrophotographers start out with a telescope under 6” in aperture – considered by most to be a puny size for visual astronomy. However, one can produce fantastic results with a telescope as small as 50mm or even a wide-angle telephoto lens.
It is important to understand that unlike visual astronomy, where aperture rules, for deep-sky astrophotography optical speed(related to focal ratio) rules. Some of the greatest astrophotography pictures ever taken were done using a small camera lens – so size is not the primary consideration.
The need for speed is the result of how signal-to-noise-ratio (SNR) is measured. Compared to daylight targets, deep-sky objects are extremely dim. The more photons we capture in our pixels during our available time under the stars, the better our picture will look. We measure the number of photons captured in terms of SNR. More photons counted in the pixel equals more SNR. More SNR makes for a smoother picture. Optical speed refers to how fast the photons are flowing through the system and getting into our camera’s pixels. The faster the better.
While fast optics can increase “signal,” to reduce noise involves other considerations. Reducing noise can best be accomplished by photographing under dark skies without light pollution, or by using special narrowband filters.
Speed is indicated by the focal ratio. The focal ratio is the focal length divided by the aperture. Speed changes by the focal length squared. So an f/4 system is 4x faster than an f/8 system.
3: Astrophotography has a higher cost of entry than visual astronomy
The bare minimum you need to get a decent astrophotography telescope and mount (if you’re not shopping used) is about $1000, assuming you already have a suitable DSLR camera – figure a few hundred extra bucks if you haven’t obtained one yet. Compare this to visual astronomy where a decent telescope can be obtained for 1/10 as much. Sure, you can slap a camera on less-expensive telescopes with simple clock drives, but don’t expect great results or a very upgradable setup.
4: Astrophotography has a difficult learning curve
Astrophotography also requires a lot of practice before you can get great results. With visual astronomy, after just a couple nights you can spot tons of planetary and lunar detail and with practice deep-sky observing will become easy.
On the other hand, I have seen astrophotographers with rigs costing as much as a new Tesla(!) who do not seem to understand the fundamentals of image processing. Contrary to what many neophytes seem to believe, there is more to image processing than upping the brightness/contrast. I would recommend practicing on somebody else’s raw image data before you even go outside to take your own pictures. Processing, not equipment, is often what makes the difference between a bad or mediocre astro-image and an Astronomy Picture of the Day. You can get great results with a modest setup and horrible results with the best telescope in the world – it all depends on whether you’re willing to take the time to learn what you’re doing.
Bad (above) versus good (below) processing. Same data, radically different results.
5: A good astrophotography telescope is not always a good visual telescope, & vice versa
Computerized German equatorial mounts – a de facto necessity for serious deep-sky astrophotography – are also great for visual astronomy. However, it’s a different story when it comes to the telescope itself. Here are some examples of why some of the popular types of visual astronomy telescopes might fail for astrophotography:
A short, inexpensive achromatic refractor is a fun visual telescope, but the purple bloating it produces on stars in astro-images will be an eyesore. So a good refractor for astrophotography must use ED glass(a kind of lens) to control chromatic aberration. Many ED refractors made for astrophotography have optimizations and compromises which end up making them poor choices for visual astronomy (particularly abnormally high weight), though most are at least acceptable.
A fast Newtonian reflector meant for visual astronomy will typically have as small of a secondary mirror as possible to minimize contrast loss. However, Newtonian astrographs can have secondary mirrors almost half the size of the primary, and often it’s impossible to reach focus with an eyepiece in them without additional accessories! A visual Newtonian with its smaller secondary and visual-optimized focal plane will struggle to illuminate or reach focus with most deep-sky camera or DSLR chips.
A Ritchey-Chretien telescope is a great choice for astrophotography of galaxies and small star clusters. However, with its massive secondary mirror, off-axis aberrations, and again the focal plane distance, a Ritchey is a pretty poor choice for more than quick glances at the sky. A Schmidt-Cassegrain telescope’s off-axis aberrations, as well as the troublesome mirror flop and image shift makes it a more difficult – though not useless by any stretch – choice for astrophotography, while for visual use they’re quite good.
With all this said, let’s get on to what equipment you need specifically.
Top Telescopes for Astrophotography
Refractors Vs. Reflectors
Refractor type telescopes are great for a beginning astro-imager. Since you basically don’t have to deal with collimation, flexure, or cooldown, you’re much more likely to get good images starting out with a refractor than with a reflector. Furthermore, refractors at small apertures are much lighter in weight than a Newtonian reflector so you don’t need as big of a mount.
However, refractors aren’t perfect. An achromatic refractor may be acceptable for visual astronomy, but the chromatic aberration of an achromat will result in bloated and purple-rimmed stars in your astrophotos. Thus, you need to spend money on a refractor which at least possesses extra-low dispersion (ED) glass or preferably a triplet if you can afford it. Most less-expensive imaging refractors also suffer from field curvature, which can make it look like you are zooming towards or away from the center of the image at warp speed like in Star Trek. This can be solved with a relatively inexpensive field flattener, however.
Refractors sold for astro-imaging typically have either short focal lengths or long focal ratios due to their small apertures. The result is that you are either stuck with a telescope that has too low of a focal length to go after small targets, or something that requires long exposure times to capture as much due to its long focal ratio. There’s also the problem of dew accumulating on your objective lens.
Fast Newtonian reflectors like the kind used for astrophotography require extremely precise collimation, and a coma corrector is almost mandatory. Ritchey-Chretien reflectors are even harder to collimate than fast Newtonians, and a field flattener like the kind used in a refractor is preferable – although they do not suffer from coma, the field of view in your images can be curved and may give the impression that you are headed towards the target object at warp speed.
Flexure and loss of focus while imaging is also a bigger problem with both major reflecting telescope designs compared to with refractors, and a reflecting telescope also typically needs time for its mirror to acclimate to cool outdoor temperatures – small refractors have basically instant cooldown time for all practical purposes under most conditions. A large Newtonian or pretty much any Ritchey-Chretien will require autoguiding due to the weight and long focal length of such an instrument, which further adds to cost – don’t be fooled by the cheapness of the scope itself!
However, both Newtonians and R-Cs have big advantages over refractors. A fast Newtonian will allow you to capture far more with a given time exposure than with a small refractor, and a Ritchey-Chretien’s long focal length makes it great for imaging small targets like globular clusters and galaxies. Both designs also will of course have superior resolution to a small refractor thanks to their usually-large apertures, and reflecting telescopes don’t have to deal with dew nearly as much as refractors do.
If you are a beginner and must get a reflector I would recommend a 6” or 8” f/4 Newtonian like the ones listed below. Ritchey-Chretiens are great scopes, but you really need to learn how to do astrophotography with something simpler and easier to use first – this might be one of the refractors listed earlier, which could double as a guide scope piggybacked on your R-C later.
Catadioptric telescopes carry many drawbacks for astrophotographers. Maksutov-Cassegrains are out of the question due to their super-long focal ratios, while Schmidt-Cassegrains suffer from image shift and mirror flop. Unless you can afford an expensive EdgeHD, Rowe-Ackermann Schmidt, or corrected Dall-Kirkham telescope, catadioptric telescopes are probably not a good idea for beginners to image with.
All things considered, though, for beginner astro-imagers I would really recommend a refractor telescope for astrophotography over a reflector just due to the ease of setup and use, but if you must get a reflector we’ve provided some good selections too.
The Evoguide 72 is basically the same as the Astro-Tech AT72EDII and other low-cost 72mm ED doublet refractors – they’re all made in the same place.
The Evoguide is great for wide-field deep-sky imaging, with its focal length of just 420mm. However, its low-cost objective lens means it doesn’t have the best color control nor the sharpest images, so forget about doing much serious imaging of globular star clusters, nor of galaxies besides M31 and M33 (or the Magellanic Clouds if you live near or south of the equator).
The scope does lack a finder, but with such a short focal length you don’t really need one. It basically is a large finderscope in itself.
With such a low focal length, low cost, and low weight, the Evoguide 72 is a really great astrophotography scope to get started with. However, as with low-cost mounts, don’t expect a scope like this to last you too long once you get into serious imaging. You get what you pay for. But for this price, the Sky-Watcher Evoguide 72 is one of the best beginner astrophotography telescopes you could get.
The f/4 Newtonian astrographs sold by Orion are all rebadged versions of the generic GSO Newtonians you can find under various other brands. Orion claims their 6” f/4 has additional reinforcement beneath the focuser, but this may or may not matter for you as a beginner.
The 6” f/4 Astrograph has a claimed weight of 12.7 pounds. But once you add a guide scope, camera, and coma corrector the weight is going to probably pass 15 pounds, which means you’re on the verge of outgrowing an HEQ5-class mount.
The 6” f/4 Astrograph’s main flaw is a bit of an unusual one. The tube is very short – so short, in fact, that if you put a heavy camera, coma corrector, and guide scope on you will not be able to slide the tube rings far enough forward to balance the scope. This may or may not be an issue depending on your rig but I would err on the side of caution. A DSLR is probably not the best choice for this scope.
If you are confident that you won’t have balance problems with your DSLR (or just use a lightweight CCD and guidescope) the Orion 6” f/4 Newtonian Astrograph is a great choice as an astrophotography telescope.
The Sky-Watcher ProED 80 may be only a little bigger and more expensive than the Evoguide 72, but it boasts massive improvements in performance.
For one, the ProED’s focal ratio is f/7.5 as opposed to the f/5.8 of the Evoguide. While it will take you longer to get the same amount of data for a given object, the ProED 80’s longer focal ratio means that the edge of the field of view is much better looking without purchasing a field flattener, and with 600mm of focal length you can actually get some decent images of galaxies and globular star clusters – the ProED 80’s higher optical quality also enables this.
The ProED 80 is also a fantastic visual telescope should you prefer to look at the sky with your eyeball rather than a camera at least some of the time. It comes with a 2” star diagonal, a couple eyepieces, and a nice big 9×50 finderscope to enable visual use right out of the box.
The 8” f/3.9 Newtonian Astrograph is a nice astrophotography telescope – and a surprisingly good one for visual use as well. It’s a surprisingly affordable and good scope for astrophotography – basically a scaled-up version of the 6” version and thus without as much of the balancing issues (and it also include a cooling fan which the 6” f/4 Astrograph lacks).
The only major downside (besides the inevitable coma) is this scope’s weight. Orion claims a weight of 17.5 pounds, but in actuality, with the included 50mm finderscope it’s about 20.3 pounds – removing the finder will bring it down to 19.3, but adding a guide scope, camera, coma corrector, etc. will result in at least a 24-pound rig. So the 8” f/3.9 Newtonian Astrograph is really at home on an EQ6-class mount or bigger.
While it does require a big, heavy-duty mount, the Orion 8” f/3.9 Newtonian Astrograph is a great scope to image with, even for those just getting started in the hobby.
The ProED 100 is similar in most aspects to the 80mm version apart from the larger aperture and longer focal ratio. At f/9, however, it is going to require rather hefty exposure times as it is the slowest scope on this list. The good news about it being an f/9 is that you should be able to do fine photos without a field flattener. Additionally, 0.85x reducer/flattener combos are available to bring the scope’s focal ratio down to f/7.65, though spacing your camera correctly with such devices can be difficult.
At about 9 pounds, the ProED 100 is still easily capable of fitting on an HEQ5-class mount, though the long tube is more likely to be affected by wind.
If you don’t mind the rather long tube and resulting focal ratio, the Sky-Watcher ProED 100 is a fabulous instrument for both visual and astrophotographic use.
Ritchey-Chretiens are difficult for beginners to use due to their long focal lengths and need for precise collimation (which is rather complicated to achieve). However, as a relative novice, I was able to get the hang of this scope and even use it on my HEQ5 mount. The trick is precise balancing, and to only adjust the secondary mirror when collimating.
On an EQ5-class mount you really can’t shoot for longer than 60 seconds at a time with this scope without having too many tracking errors (even with autoguiding which is required for this scope), but a heavier-duty mount will, of course, do better with longer exposures.
Besides the greater need for precise tracking, guiding and collimation the only downside of this scope is that a lot of large nebulae and star clusters won’t fit in the field of view anymore, and the f/9 focal ratio means long total exposure times are required. However, it is a workable scope for a beginner.
Astrophotography Telescope Accessories
Field flatteners fix the weird elongation of stars you get at the edge of the field of view with most refractors, as I mentioned earlier. You might be able to see it at the left and bottom edges of this image I took without a flattener:
Don’t see it? Here’s a close-up:
If you think this is obnoxious, you should see what a starfield, nebula, or the Andromeda Galaxy looks like. It is like you are flying towards the center of the field at lightspeed. The effect is worst of all on full-frame DSLR cameras and with fast refractors. The scope I took this with is a relatively slow 76mm f/8, so the field curvature isn’t as bothersome as with a faster instrument.
Field curvature occurs to a lesser extent in Ritchey-Chretien reflectors, so if you’re using one of those you may benefit from a flattener as well
Our two recommendations for flatteners are:
Orion 8893 Field Flattener – Inexpensive, works well, but you may have to play with the spacing using thread-on extension tubes and adapters.
Explore ;Scientific Field Flattener – Works great, spacing is usually a nonissue with DSLR cameras.
There are also focal reducer/flattener combos, but they are more sensitive to spacing and do not offer quite the same edge-of-field correction as regular flatteners.
A coma corrector is really a necessity for astrophotography with a fast Newtonian reflector. Without one, stars at the edge of your images will appear as fuzzy “seagulls” and you will either have to ignore them or crop the image.
Here are our coma corrector recommendations:
Baader Planetarium MPCC – Lowest Price, Choice Under $225:
The Baader MPCC is a decent coma corrector, but it adds spherical aberration to your telescope. Depending on your camera, said resulting optical defect may or may not be visible. People swear by the MPCC, but I would recommend getting a better corrector if you can afford it.
Explore Scientific HR Coma Corrector – Choice Between $225-$450:
This coma corrector is great because not only does it not add spherical aberration, but it also can be used with an eyepiece should you want to look through your telescope, and it accepts 2” filters. The top is also tunable to adjust the coma correction precisely.
Tele-Vue Paracorr II – Choice Above $450:
The Paracorr is the first widely-available and simply the best coma corrector out there. It has superior mechanics and light transmission, as well as better correction than the ES HR unit. Highly recommended.
Unless you are powering your rig via a wall socket (AC current), you will need a big hefty battery to run at least your telescope and possibly your computer and camera too.
For those with small budgets and interested in a more portable setup, we recommend the power supplies below. However, if you have more to spend and/or a hefty vehicle you might be better off with a deep-cycle marine battery or the like.
Celestron PowerTank – Choice Under $100
This battery is cheap and with 2 ports can easily power your scope and a computer (provided you use an inverter). However, the lead-acid design will only last you 5 years or so until it can no longer hold a charge, and using an inverter is going to suck up a lot of power. However, this battery comes with bonus features: In an emergency you can jump your car with it, and it has both a red flashlight and white LED spotlight.
Celestron PowerTank 17 – Choice Between $100-$175
This is basically the same as the smaller PowerTank but with a heftier battery and a built-in radio, if you want to listen to the radio while imaging or something. The radio can be useful on those nights where the weather isn’t very certain and you need to listen to the weather radio.
Celestron PowerTank Lithium Pro – Choice Above $175
This battery may not have all the bells and whistles of the regular PowerTank and only one cigarette lighter port, but it has a smaller DC port and cable to power most mounts. It has the same capacity as the PowerTank 17 but with the advantage of running on LiFePO4 technology which will last you decades. It also is small enough to be strapped to your mount’s tripod legs and comes with a strap to do so. Lastly, the Lithium Pro includes USB ports to charge your smart devices with.
Cables, Adapters & Miscellaneous Items
With any astrophotography rig you’re going to need cables and other electrical devices. There are so many possible setups just based on the equipment we’ve listed that it’s impossible for us to cover everything or give specific recommendations, but here are some of the things you’ll need:
- Camera control cable (if using a DSLR with a computer) or intervalometer
- Mount control cable (if plugging your mount into your computer), either RS-232 or EQDIRECT
- AC or DC power port for mount
- Adapter for your laptop to charge from a portable power supply
Additionally, you’ll probably want an additional dovetail to piggyback your guide scope on top of your main telescope, and clamps or screws to attach said guide scope to the dovetail.
For almost any deep-sky imaging, what you are typically doing is taking exposures anywhere between 15 and typically 120 or so seconds and stacking them. For stacking you need a software program, and for almost everything that’s DeepSkyStacker. DSS is free, and it allows you to stack images and add in calibration frames – as well as doing some very simple and basic image processing. However, for real processing you need more than just DSS.
Most people begin image processing with the free software GIMP or use Adobe Photoshop. While these programs are great to start out with – especially for those already familiar with daytime photography and image processing – they are limited in the ways they can improve astronomical imaging. A better solution is PixInsight. The 60-day trial is free; the full version is quite expensive but well worth the money.
Another piece of software you might want to consider is NINA. NINA – a free, open-source software application – can allow you to automate your entire imaging setup, to the point that all you need to do is polar align, focus, and then select objects and exposure length – it even star aligns your mount for you!
The below books are often cited as great resources for both beginners and more advanced photographers.
Building an astrophotography setup takes lots of thought to get everything to mesh together. A good astrophotography setup is a cohesive system where every piece of equipment has features that compliment each other. We hope that this article made this process easier by explaining some of the ways that equipment needs to fit and what equipment you need to get started as easy and hassle-free as possible.
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