Not to mince my words, but I have never been a fan of the DXO sensor scores for cameras. They place far too much emphasis on the technical aspects of digital sensor performance and nothing on the aesthetic qualities of an actual photograph. In my world, cameras are for making photographs (seems to me that is what they were designed for). Worrying about whether your camera sensor has half a stop more Dynamic Range is a black hole that is the antithesis of good image-making.
With that caveat out of the way, DXO has just ranked the Canon EOS R3 the best full-frame low light performing camera on the market today. Headlines such as this are usually nothing more than clickbait, but there was one very interesting piece of information buried in their review that corroborates exactly what found in my post here on the EOS R3 Noise performance.
I said “RAW files from the Canon EOS R3 and the Canon EOS 1DXMK3 were compared and analysed at 100%, 200%, 400% and 800% magnification side-by-side in Lightroom. Directly comparing the RAW files shows no discernable or appreciable difference in noise between ISO 50 and ISO 51,200. Side by side, it is impossible to pick one from the other in a blind test. At ISO 102,400 the Canon 1DXMK3 has a very slight advantage in grain structure; although it is likely this difference would never be visible in real world photographs. What this demonstrates is that noise levels have more or less plateaued in digital sensors.”
DXO said “The Canon EOS R3 has a strong response in color sensitivity, particularly at low ISOs compared with the Canon EOS-1DX Mark III. Indeed it outperforms the Canon EOS-1DX Mark III throughout the majority of the sensitivity range with the exception being at the manufacturer’s ISO 51,200 and 102,400 settings, where it drops below that camera by 0.4 and 0.3 bits respectively.”
What I find interesting about DXO’s findings is that we do concur on the 1DXMKIII outperforming the R3 (just) at the extremely high ISO of 51,200 and 102,400 (although personally, I can see no appreciable difference at 51,200). DXO call the R3 the winner between ISO 50 and ISO 25,600; but again, in side-by-side comparisons, I can see no difference, and spotting the difference in print is impossible. What all of this points to is that the differences at the top end of sensor design are now so small that comparisons are pretty much meaningless. Either camera will give you outstanding industry-leading results at pretty much any ISO.
DXO’s final conclusion: “… the Canon EOS R3 is certainly a compelling contender for its intended market. Not only does it have excellent dynamic range at key low, mid and high sensitivities, it has the best low light performance of any full-frame camera in our database. This makes the Canon EOS R3 a very attractive option for Canon EOS-1DX Mark III users transitioning over to Canon’s mirrorless RF system and it’s a solid option for any photographers new to the Canon brand.”