Somewhere in the back of a closet around here is a shopping bag nearly full of mount adapters I no longer use. The worst of them is a Novoflex that allows Nikon lenses to
hunt endlessly autofocus on Leica SL cameras. When Canon averred that the EF-RF adapter would permit full function of EF lenses on RF-mount cameras, I should have read more closely. There’s a huge difference between “function” and “performance.”
Out with the 90D and 100-400mm this morning in bright light, I got consistently good results while stalking my heron friends in flight. Most of the shots I missed were due to technique. AF was fast both with and without the limiter switched on.
Pushing my luck, I headed out to the same fields in the very sunny afternoon with the EOS R and 600mm f/11. At first I got some almost-but-not-quite-sharp shots, and realized I hadn’t switched the limiter on. Once I did, the camera didn’t miss another shot except when the critter was too fast or erratic for me to hem it up within the limited number of AF points of the f/11 lens. Impressively, the camera could pick out the bird against a background of foliage.
So now I know. EF lenses on EF-mount cameras; RF lenses on RF-mount cameras. No matter what Canon says . . .