>>4013498>>4013563There is hardly any difference in high ISO performance among sensors *within the same format* over the past 10+ years. The R6 starts to show a small, maybe 1/3ev, advantage over the 5D3 at 25,600. By 204,800 it's arguably 1ev ahead of the 5D mark III, but both are unusable at that point. On any FF camera I personally consider 12,800 to be my max ISO, with 25,600 being an "emergency use only" ISO. Note that this assumes lighting which yields a normal, well centered histogram without any push/pull in post. So a scene which is low light but otherwise well lit.
If you have to push the scene...or the subject if you don't care about the background...by 1ev in post then effectively you weren't shooting at the ISO you chose, but actually 1ev higher ISO. This might sound obvious, but people miss it all the time in comparing real world high ISO shots. "Our cameras were both at ISO 3200 why does mine look worse?" Well, your scene had worse light and you had to push 2ev in post. You're really comparing ISO 3200 and ISO 12,800 shots.
You are shooting under difficult, contrasty lighting and your histograms are shifted left. Under concert conditions I would not likely consider 12,800 acceptable...for my taste...on any FF camera. My "max ISO" and "emergency use ISO" would lower than normal. Likewise, different concert scenes can vary dramatically in noise and acceptability based on how much light was falling on the subject at that moment, and whether or not you tried pushing the scene or any shadows in the scene.
>>4013501>Apparently ISO 2000 in Canon cameras is basically 1600 with added digital brighteness.Every camera does this with fractional ISOs. Hell...with ISO invariant cameras this is what happens at every ISO above base.
>>4013518More light on the subject, no attempt to push the background, and SOOC JPEGs include NR. An X-Pro 3 sensor cannot out perform a 5D3 sensor at high ISO, all other factors being equal.