Not long ago I bought a used Canon EF 400mm f/2.8L IS II in great condition off of eBay (it was pristine). For kicks, I took it outside to the street...
Yep. It's running the most recent firmware. It's impossible to shoot it at anything but f/1.4 and locks up the camera if you try to change apertures...
The R3 outputs 14-bit in all shutter modes and takes a similar (slightly bigger, actually) hit with ES compared to mechanical, so I wouldn’t call it...