Suitable cameras for astrophotography include both conventional cameras with interchangeable lenses (ILC) and dedicated astrophotography video cameras. Astronomical video cameras require a separate computer and display to focus, frame the image, and save images, as well as a telescope. In return they have good near IR sensitivity for emission nebulae and cooled sensors which reduce noise and simplify image calibration.
Many people already own a conventional ILC DSLR or mirrorless camera for daylight photography. I recommend them for astrophotography, because of their familiarity, simplicity, and flexibility. They are self contained, easy to use, and can deliver outstanding results with and without a telescope for many different kinds of astrophotographs. Some can be modified for better near IR sensitivity to capture emission nebulae.
If you already have a camera with a removable lens, all you need is a sturdy tripod to make your first astrophotographs. With sturdy tripod and a lens of 50 mm focal length or less you can make Make Milky Way or star trail images. With a longer telephoto lens, you can take sharp, clear, images of the moon. Telephoto shots of dimmer deep sky objects will require a star tracking mount. Once you are taking images, you will begin to appreciate the value of the features listed here. If you are frustrated by the lack of some of them or don’t already have a camera, use these as a guide to picking a new camera well suited to astrophotography.
There are two common types of ILCs: DSLRs and mirrorless cameras. Both can work well but mirrorless cameras have advantages for astrophotography:
These are good reasons to choose a mirrorless camera body over a DSLR if you are purchasing a camera specifically for astrophotography. If you already own a DSLR you can probably get good results with it. If you also use your camera for wildlife or sports action shots you may want to choose a DSLR and work with its limitations for astrophotography.
Sensor size and sensitivity are the most important features of your camera for astrophotography. Look for:
ILC cameras can be mounted on a telescope with an adapter usually called a T-ring. The T-ring will connect to your camera's bayonet adapter in place of a camera lens. The other end of the T-ring has an M42x0.75 mm threaded connection. If your telescope doesn't have a matching thread there are adapters to other threads and also slip-fit adapters that will mount the adapter in place of an eyepiece (1.25 or 2 inch). The telescope then functions in place of a telephoto lens on your camera.
Be aware that using a telescope or telephoto lens for astrophotography, for anything other than the Moon or Jupiter, requires a motor driven star tracking mount. Newtonian reflecting telescopes often don't have sufficient back focus adjustment distance to come to focus with a camera without additional lenses or modifications, this is especially true of DSLRs. If your telescope is a refractor or catadioptric scope, with the eyepiece at the bottom (back) of the telescope, there is a good chance that it will work with most cameras with the right adapter.
Almost always the best lens to start with for astrophotogaphy is a fast wide angle short focal length prime lens. You can get by with only a sturdy tripod without an expensive tracking mount. If your only lens is the kit zoom that came with your camera, go ahead and give it a try.
Don't be tempted to buy a super zoom camera with a built in zoom lens for astrophotography. If you already have one, give it a go. If you purchase a camera for astrophotography, an ILC gives you the flexibility of using higher quality prime lenses and telescopes. This flexibility often costs less than an all in one super zoom camera.
If you will be using a fixed tripod to start, the earth's rotation will limit your targets and the focal lengths usable by your camera. The most useful lens for astrophotogaphy from a fixed tripod is a short focal length (< 20mm) prime lens. If you only have a zoom start with it zoomed all the way out to its shortest focal length. This will let you shoot the Milky Way, star trails, meteor showers, and dramatic nightscape images.
A long focal length lens (> 135mm) can show the
moon in clear detail, but the long exposures required by dimmer targets
require a star tracking mount. A good rule of thumb for the longest
exposure that won't show obvious star trails is the Rule of 500. Divide
500 by the full frame equivalent focal length of your lens for the
maximum exposure time in seconds.
Prime lenses give better results than zoom lenses of the same quality. The more glass that starlight goes through, the dimmer and more distorted it becomes. Zoom lenses are convenient for daylight photography, but may contain more than a dozen internal lenses. If you already have a zoom, start by using it. When you notice that stars near the edge of your image look like little comets or rainbows, it's time to look for a good apochromatic/ED prime lens or even better a telescope designed for astrophotography.
If you have a mirrorless ILC, vintage SLR prime lenses can let you reach for deep space at a tiny fraction of the cost of a new lens or telescope.
For any camera there are features that will make it easier to get good astrophotography results. If your camera doesn’t have some, you can work around them. If you are buying a camera specifically for astrophotography, you should look for these and understand their value to you.
For an idea of the variety of ways that you can use a ILC camera in astrophotography see the images below. These were taken with both crop sensor and full frame mirrorless cameras. Some were on a fixed tripod and others required tracking mounts. Camera lenses from 14mm f/2.8 to 300mm f/5.6 and a 1350/89 mm f/15 telescope were used.
The image below was taken with a crop sensor Sony a6300 with a 135mm lens on a fixed tripod:
The Milk Way can be shot with a wide lens from a fixed tripod. Here with a full frame Sony a7iii and a Samyang 14mm lens:
A star tracking mount with a simple ball head for deep space images:
Image below taken with a Sony NEX-5N 16MP crop sensor camera and a 135mm vintage lens with the setup shown above.
The sword of Orion taken with a Sony a7iii, a Nikkor 300mm ED lens, and a Vixen Polaie star tracking mount:
A star tracking mount with a small telescope using a panoramic head, declination L-bracket mount, and counterweight:
The sword of Orion taken with a Sonya7iii, Redcat 250/51mm f/4.9 telescope, and the Vixen mount with a counterweight:
A fork mounted telescope with built in tracking drive for lunar close ups
Images below take with a Sony NEX-5N 16MP crop sensor camera and Questar 89mm telescope
Planetary images using lucky image stacking benefit from the fast video frame rates of astronomical video cameras, but good results are possible with an ILC camera like the Sony a6300 and a small telescope like the Questar 89mm
Image below take with a Sony NEX-5N 16MP crop sensor camera and Questar 89mm telescope
Content created: 2019-11-26 and last modified: 2020-12-09
By submitting a comment, you agree that: it may be included here in whole or part, attributed to you, and its content is subject to the site wide Creative Commons licensing.