Canon EOS R5 vs R6 Astrophotography and High ISO Comparison

Photographer Brent Hall recently went out to shoot a comparison video that a lot of Canon shooters are eager to see: the brand new EOS R5 vs the EOS R6, for astrophotography, at high ISO. Does the lower resolution sensor of the R6 give it a low-light advantage?

The answer, at least according to Hall, is yes. And he’s got the photos to prove it.

But first, a few disclaimers that he wanted to throw out there. When we spoke to him about sharing this video and his resulting images, he shared two bits of information that he said we may want to include now that the YouTube commenters have gotten their hands on his comparison and started to (uncharacteristically… of course) tear it to shreds.

Enter Brent:

  1. I didn’t downsize the R5 images in the video (and this made a few viewers quite upset, lol) as people were quick to point out that it wasn’t a fair test because downsiziing the R5 images would have reduced the noise and made it more comparable. Well, I did do that after the fact, and while, subjectively, it may have helped a bit, I still has the same results, that the R6 (again, subjectively) looked a bit cleaner at the higher isos (6400 and up).
  2. On the note of the R5, I totally forgot to take into account the NPF rule for the high megapixels, so the 500 rule doesn’t apply with high mp cameras, and it should be more like the 300 rule (you can see evidence of this with the 20 sec 3200 iso R5 images having slight star trails when zoomed in, and the trails are gone with the 8 sec 12800 iso image). Of course, like I said in the video, that has no bearing on noise levels, just me defending myself against the lovely critics of the YouTube world.

With these two points in mind, here are some (almost) full resolution sample images that Brent was kind enough to share with our readers (click to enlarge). In each of the pairs of images below, the EOS R5 image comes first, followed by the EOS R6:

20 sec, f/2.8, ISO 3200

15 sec, f/2.8, ISO 6400

8 sec, f/2.8, ISO 12800

So… how did it go? The good news is that both cameras performed admirably, even at 12800 ISO. And while there is a difference to Brent’s eye, the difference is surprisingly small given the fact that the R5 is more than twice the resolution. That’s good news: those who want the R6 are getting slightly better high ISO performance at a much lower price; and those who want the R5 are getting surprisingly good high ISO performance despite the bump in resolution.

To dive deeper into the images, explore them at 100%, and hear Hall’s thoughts on this test, be sure to check out the full video up top or pixel peep the samples for yourself.


Image credits: Photos by Brent Hall and used with permission.

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