The camera section is contributed by Aaron Tragle, an astrophotographer, and the rest of the article is written by our expert writer and renowned astronomer, Zane Landers. All product recommendations made are based on the experience and expertise of the writers, not by any kind of short and inaccurate research.
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. You may consider this article as an all-around astrophotography guide, not just about astrophotography telescopes or cameras.
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.
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 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 5 Equatorial Telescope Mounts for Astrophotography
The #1 most important item for astrophotography of deep-sky objects is your equatorial mount. The mount should always be the most expensive part of your setup. If you can afford nothing but a mount, just get an adapter and put your DSLR/lens on if you can, then upgrade to a scope later. The mount rules all.
Almost all best astrophotography mounts sold today, apart from a few premium offerings outside the scope of this article, are computerized German equatorial mounts. These astrophotography mounts are the most lightweight, versatile, and inexpensive option available to amateurs.
The EQM-35 is a relatively new entry by Sky-Watcher in the world of astrophotography mounts. It’s basically an Orion SkyView Pro/Celestron CG-4 mount with motors and GoTo installed.
The EQM-35’s lightweight and low cost make it great for beginning astrophotographers. And just like more expensive equatorial mounts, the EQM-35 is fully compatible with autoguiders, PC control software and anything else you need for imaging.
Sky-Watcher mysteriously claims a 22-pound weight capacity for the EQM-35, yet also doesn’t recommend shoving anything remotely near that heavy onto it. I put a Celestron C8 (about 14 pounds) on the EQM-35 and it was not the steadiest for visual astronomy, so I’d wager that in practice, the EQM-35’s weight capacity is closer to 15 pounds for visual use, and under 10 pounds for astrophotography. Thus, you are not going to be putting anything more than a telephoto lens or a small refractor on here for visual use.
If you’re not concerned about outgrowing its capacity, the Sky-Watcher EQM-35 is a good choice for a budget astrophotography mount.
I’m probably going to get a lot of angry astrophotographers in the comments questioning how DARE I recommend the “horrid AVX” to beginners, but I’m doing it anyway.
Despite all the hatred it seems to receive, the Advanced VX is a workable – if not perfect – mount. It uses servo motors rather than steppers, and the declination axis has no bearings whatsoever – the result is that it has lots of backlash when slewing the mount around the sky and during autoguiding. However, there are plenty of fine images taken with Advanced VX mounts. If you can swing the extra $250 to buy the Sky-Watcher HEQ5 Pro I would definitely recommend doing so, but there is absolutely no shame in owning or using a VX.
The Advanced VX’s 2” diameter steel tripod legs are more stable in windy conditions than the 1.75” legs of similar mounts, and the Celestron NexStar+ hand controller is easier to navigate than the SynScan controllers of Orion and Sky-Watcher mounts (though this is irrelevant if you control the mount directly via a laptop).
I would not recommend loading anything over about 14 pounds for imaging on the Advanced VX. But for visual use, you can max out its 30-pound capacity with no issues – something to consider if you plan on using the mount with another telescope.
This is the mount that I learned astrophotography on and a really solid choice. The Orion Sirius is functionally identical to the HEQ5 Pro – the only difference is that Sky-Watcher has better customer support and there seem to be more users of the HEQ5 Pro version than the Sirius out there.
The HEQ5 Pro has excellent tracking and guiding accuracy – it often guides at under an arc second – and is still quite lightweight and portable. The HEQ5’s 1.75” tripod legs are lighter than the Advanced VX so it does theoretically suffer some minor payload capacity loss, but this is made up for by its increased tracking accuracy and other features. The HEQ5 is compatible with EQMod drivers and a variety of hardware accessories to allow you to get the most out of it and have plenty of room to grow, and there are some who have made the belt and tuning modifications to further improve tracking and guiding accuracy with this mount.
I would recommend putting a scope no heavier than 15 pounds or longer than 1200mm in focal length on the SkyWatcher HEQ5. It struggles with my 6” f/9 Ritchey-Chretien, for instance, which is right around those limits.
The original EQ6 mount was more or less a scaled-up copy of the HEQ5. With the EQ6R Pro, however, Sky-Watcher has added a belt drive upgrade (previously only available as a warranty-voiding mod for skilled DIYers), improved polar alignment features, and ergonomic enhancements. The EQ6R’s payload capacity is no slouch, either. For visual astronomy you could load up to 44 pounds, while for astrophotography you should be able to fit between 20-25 pounds before vibration and other issues start to occur.
Downsides? Weight. The mount head alone is 38 pounds, with the tripod coming in at another 16.5 pounds. Maneuvering the mount head onto the tripod is difficult, to say the least, and then there’s the counterweights and your scope itself.
While the SkyWatcher EQ6R is certainly portable, it would be good to store it on a dolly or in a permanent enclosure/observatory if possible.
The Sky-Watcher version of this mount doesn’t seem to be available in the US, unfortunately, so right now you can only get the Orion.
The Atlas Pro (also sold as the Sky-Watcher AZ-EQ6 outside the US), like the EQ6R, uses belt-driven stepper motors for superior accuracy.
The Orion Atlas Pro AZ/EQ-G also has a few pounds of extra capacity over the EQ6R and an alt-az mode that allows it to hold and track with 1 or 2 telescopes for visual astronomy, a nice bonus.
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.
Choosing a camera for Astrophotography
Choosing a camera for astrophotography is a big decision that takes lots of thought and decisions made. What is your budget? What telescope would you be mating the camera to? These are some of the questions you will have to ask yourself before finding the perfect camera. This segment will help provide guidance for making this decision.
Matching a camera to a telescope
Matching the correct camera to the correct telescope is an important part of astrophotography and matching incorrectly can make the already difficult learning curve seem more like a cliff. There are two major considerations you need to make when choosing a camera, Pixel Size and Sensor Size. Pixel size along with the focal length of the telescope determines how large one pixel is relative to the sky, also known as Image Scale.
Using one of my most used astrophotography telescopes as an example, my telescope has 460mm of focal length and my camera pixel size is 3.8 microns. Using the formula below, I calculated that my image scale is 1.71 arcseconds per pixel or 1.71”/px. You can calculate your image scale using the formula below.
(Pixel Size / Telescope Focal Length) x 206.265 = Image Scale
Image scale is important because the smaller it is, the harder it will be to track your telescope accurately and more effort will be needed into getting your autoguiding perfect.
Now using the formula stated above, practice using image scale to match a camera to a telescope. Calculating image scale requires knowing two figures which are provided by telescope and camera resellers, you have to know the focal length and the pixel size of your camera and telescope. In the example below there are two telescopes, an Orion 6” F4 Newtonian Astrograph and an Orion 10″ F3.9 Newtonian Astrograph. There are also two cameras, a ZWO ASI1600MM Pro and a Nikon D5100. Using the formula above we can calculate the image scales for the combinations of cameras and telescopes.
|ZWO ASI1600MM Pro||Nikon D5100|
|Orion 10″ F3.9 Newtonian Astrograph||0.78”/px||0.99”/px|
|Orion 6” F4 Newtonian Astrograph||1.65”/px||1.31”/px|
The table above lists the image scales using all the possible combinations of cameras and telescopes in this example. From experience, I would not recommend a pixel size of any less than 1”/px to any beginner. Why do you ask? There are many reasons why I say this. The most important reason is tracking accuracy. The smaller your pixels, the better your tracking, polar alignment and guiding will need to be. Another reason would be that this limit helps to prevent you from getting a telescope too big for your mount. Larger scopes typically make image scale smaller due to the increase in focal length.
The second factor to consider is Sensor Size – this mainly breaks down onto what you want to image. If you’d like to image large, expansive nebulae and star clusters, you will probably want to match a camera with a large sensor size to a telescope with a focal length in the 400-600mm range. On the other hand, if you want to image galaxies and planetary nebulae you should consider getting a longer focal length telescope (600-1000mm) and a camera with a medium-sized sensor.
Top Cameras for Astrophotography
DSLRs vs Cooled OSCs
For beginner astrophotographers on a budget, we recommend DSLRs specifically from Canon and Nikon. However, the Canon models have some glaring issues that put Nikon ahead of Canon for astrophotography. The most important difference is that Nikon cameras typically use much more sensitive Sony sensors for their cameras.
We would have recommended Sony DSLRs due to the incredibly low noise sensors as well, but they have a feature gone rogue dubbed “Star Eater” in their software. Star Eater is the result of a heavy-handed noise reduction algorithm in the software of the camera that can mistake faint stars as noise and completely remove them. Nikon’s cameras thankfully do not have this issue.
Above about $500, we are able to start venturing into purpose-built cameras with two-stage TEC cooling that reduces noise by orders of magnitude. These cameras are commonly called “Cooled OSC” cameras, OSC meaning One-Shot Color. Two-stage TEC cooling allows for cooling to winter temperatures during the sweltering heat of summer, which greatly reduces noise. TEC stands for thermoelectric cooling. TEC-cooled cameras use a number of thermal effects to cool a surface.
These Cooled OSC cameras also typically use the already low-noise sensors used in some of the DSLRs we recommend to reduce noise even further. The biggest disadvantage of OSC cameras is that a laptop computer is mandatory to control the entire process, whereas with a DSLR you can get by with just an intervalometer. The laptop requirement and the TEC cooling also means your rig will consume more electrical power than a DSLR-based one.
Our DSLR Recommendations:
In the Nikon camp we recommend two DSLRs, those models are the D5100 and D5300.
I have personally owned both of these DSLRs and can tell you they are a great way to start astrophotography. The D5300 has 3.8 micron pixels, which is best for medium to short focal length telescopes.
These cameras have ultra low noise Sony sensors that are suitable for long exposure imaging. The Nikon D5300 plus other select models have the advantage of having the low noise Sony sensors found in the Sony line of DSLRs while lacking the aggressive star eater noise reduction that Sony has baked into their firmware.
The D5100 offers all the great features of the D5300 but with larger 4.8 micron pixels – ideal for longer focal length telescopes than the D5300 can handle.
Otherwise, the two cameras are rather similar – like the D5300 the Nikon D5100 has an ultra low noise Sony sensor, and mostly identical specs.
We recommend this camera only to astrophotographers with shorter focal length systems; this camera has very small pixels at 2.4 microns. Such small pixels make image scale very small at even medium focal lengths, at 500mm you already are under 1”/px.
This camera has a very high QE (Quantum Efficiency) at 84% which makes for a higher SNR. Quantum efficiency is the rating for how many photons that hit the sensor are actually detected. For the 183, the QE is at 84% meaning that for every 100 photons to hit the sensor 84 get recorded.
A downside is that this camera has a small sensor at only a 1 inch diagonal.
We recommend this camera only to astrophotographers with longer focal length systems; the image scale with this camera stays above 1”/px until you hit 950mm of focal length!
The pixels are much larger than the ASI183MC Pro at 4.6 microns. The ASI294MC Pro also boasts an extremely low read noise(noice generated by the camera system) of only 1.2e, which allows for short exposure imaging if your tracking isn’t very good. It also allows for a method of imaging called lucky imaging where you take hundreds of short exposures of an object at high focal length hoping for atmospheric seeing to be good for a second or two and get great detail out of small, relatively faint astronomical objects.
Aren’t these features more than enough reasons to buy the ZWO ASI294MC Pro as your astrophotography camera?
If you must have a Canon, we recommend the Canon T6i. The T6i has a medium pixel size of 3.7 microns, which helps beginners who may not have the best tracking and polar alignment accuracy. The T6i also has a sensitive and low noise sensor relative to other Canon models. However, it is not quite as good as the Nikons.
If you have a camera identical or similar to one of the ones already mentioned (most of the Canon Rebel Ti series cameras for instance are pretty similar), you’re all set. As with any DSLR, all you need is a T-ring and T-adapter to connect your DSLR to your telescope, an intervalometer or PC control cable, and you’re set.
Choosing Autoguiders & Guide Scopes for Astrophotography
Autoguiding with modern astrophotography gear is really quite simple. You basically just need to get your guide camera and scope, attach the guide scope and focus it, and plug everything in. Then guiding is as simple as opening up PHD 2 software, calibrating and selecting a guide star, and then start guiding. It’s really simple!
Without autoguiding, exposures longer than 20-30 seconds with most telescopes and mounts will turn into a blurry, smeared mess.
A guide camera automatically tracks a target star to compensate for tiny amounts of drift and tracking errors almost any mount will produce. You typically use the free software PHD2 to do this.
Guide cameras are usually best if they’re monochrome, but a color camera can work just fine too. I personally use a color camera for autoguiding.
Guide cameras must always have both USB and ST-4 ports to plug into your computer and telescope mount respectively. Some people ditch the ST-4 port using specialized software but most imagers don’t and the complications are not worth the savings.
Top 2 guide cameras for astrophotography
ZWO ASI 120MC-S (Choice under $150) – Lowest price, and also a decent color planetary camera for beginners.
ZWO ASI 120MM Mini (Choice between $150-$200) – Cheap, monochrome design better for guiding, small size.
A guide scope is nothing more than a small refracting telescope which piggybacks on top of your main telescope optical tube and rides in an adjustable bracket to align it with your telescope. It’s basically a finderscope but typically larger and without an eyepiece.
Guide scopes are best when they’re as large in aperture and long focal length as possible – however, budget and the weight capacity of your mount are going to limit how far you can go with this.
Off-axis guiding, which uses a small prism to guide directly using the light of your main telescope, is not recommended by us to beginners due to the higher cost and the difficulty of focusing both the guide cam and main camera at the same time, among other issues.
Large guide scopes (>50mm) are typically meant to be piggybacked on top of your main telescope using plates/clamps/rails and other hardware, but all the ones listed here fit the standard finderscope shoes on most telescopes.
All of the cheap guide scopes sold nowadays are really the same, even if they have weird or generic brand names. We’ve selected the following ones to give you the best deals without sacrificing quality.
Top 3 guide scopes for astrophotography
Meoptex 50mm Mini Guide Scope (Choice under $75) – Cheapest, will work with scopes up to around 800mm focal length – despite what the advertising says it’s not great for scopes longer than that. Above 800mm you will need a bigger/longer guide scope. The 50mm Mini works just fine, but beware that there is no focusing system and you focus by pulling the camera out of the drawtube and installing a small metal parfocalizing ring – primitive, but functional.
SVBONY 60mm Guide Scope (Choice between $75-$100) – The larger aperture of this guide scope allows you to guide on fainter stars, and the longer focal length allows you to guide accurately with scopes up to about 1200mm of focal length, which is where it usually caps out from my experience. Unlike the Meoptex 50mm, this guide scope has a real helical focuser and guide rings, and has a longer bracket to allow it to be piggybacked on top of clamping systems and rails. I personally use this model.
Astromania 70mm Guide Scope (Choice Above $100) – A scaled-up version of the 60mm SVBONY. Works well up to around 1600mm focal length and can guide on even fainter stars than a 60mm guide scope. The only downside is that the weight is starting to climb a little.
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!
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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