Choosing a Camera for Astrophotography — Part 1

The author imaging at Grasslands National Park in 2019. Jupiter, at right, and Saturn, at left, flank the Milky Way. Altair is the bright star at top. Sony a7III at ISO 6400 and Venus Optics 15mm lens at f/2. LENR on. Orton Glow effect added with Luminar Flex.

Reflex vs. Mirrorless

The best camera to begin shooting the stars may be the one you already own. But here is the first in a three-part series of tips for picking a new DSLR or mirrorless camera for astrophotography.

What camera is best for shooting stars? Bloggers and YouTubers will regale you with options for cameras for capturing the night sky. Many will recommend purchasing a camera dedicated for the purpose, likely one of the new generation of cooled astro-cameras that have become more affordable in recent years, and they are certainly excellent.

But I advise beginners stay with a standard digital single lens reflex (DSLR) camera, or one of the new mirrorless cameras all the major camera manufacturers now offer. For convenience in this series, I will refer to those as DSLMs — digital single lens mirrorless cameras.

DSLRs and DSLMs have the advantage of being versatile — they can be used for all kinds of astrophotography, from nightscapes of the Milky Way to telescopic close-ups of deep-sky objects. Plus, they can be used for every other form of photography, so their “spousal approval” rating is high. You aren’t spending hundreds or thousands of dollars on a camera that can do only one thing — capture nebulas and galaxies.

I shoot all my astrophotos with cameras from Canon, Nikon and Sony, and I have yet to exhaust their potential. DSLRs and DSLMs are much easier to use than dedicated astro-cameras, as they are powered internally and don’t need a separate computer or specialized software to operate in the field.

DSLR vs. DSLM

With mirrorless cameras now offered by all the major camera brands, it does seem that this style of camera is the way of the future, with DSLRs that use reflex mirrors to be phased out.

However, for our purpose either type of camera can do a fine job. DSLRs have the advantage of an optical viewfinder to look through, which can aid in framing a scene at night. But DSLMs have electronic viewscreens that are often much brighter than the “live view” screens of DSLRs, making it easier to frame night scenes on their rear screens.

The latest models of DSLMs have battery life as good, if not better, than DSLRs, allowing two to four hours of long-exposure shooting.



DSLRs and DSLMs
Two popular DSLR cameras for astrophotography are the Nikon D750 and Canon 6D MkII (on the left), each 24- to 26-megapixel full-frame cameras. On the right are two superb full-frame mirrorless DSLM cameras for astrophotography, the Canon EOS Ra and the Sony a7III.

Cropped vs. Full Frame

The other consideration with either camera design is whether it uses a “full-frame” sensor the size of 35mm film, or a smaller sensor, usually one the size of the old APS (Advanced Photo System) film format. APS “cropped-frame” cameras are less expensive but are usually more prone to noise at the high ISO speeds we typically use in astrophotography.

Noise is our enemy, adding a visual grittiness, colored speckling, and odd artifacts such as banding and discoloration to our images, especially visible in dark foregrounds in nightscapes.


Small or Big Sensor
Cropped-frame cameras, such as the Canon 60Da on the left, have sensors about 24x15mm in size. Full-frame cameras, such as the Canon 6D MkII on the right, have sensors 36x24mm. Credit: Canon

Today’s generation of 24-megapixel cropped-frame cameras have smaller pixels than 24- to 30-megapixel full-frame cameras. While they resolve fine detail better, smaller pixels collect less light, for a lower “signal-to-noise” ratio.

However, today’s APS-format cameras can certainly work very well for astrophotography and are more affordable than full-frame cameras.

While we don’t need advanced features for astrophotography such as high-speed burst shooting and improved auto-focus, cameras farther up the product line usually have better circuitry that is less prone to noise. Low noise is key for us. So, no matter the sensor format, buy the best camera you can afford.

The question then is, is one brand better than another?

Read Choosing a Camera for Astrophotography – Part 2.

All Image Credits: Alan Dyer

About Alan Dyer

Alan Dyer is an astrophotographer and astronomy author based in Alberta, Canada. His website at www.amazingsky.com has galleries of his images, plus links to his product review blog posts, video tutorials, and ebooks on astrophotography.

Related posts