This is most likely a rhetorical question. I was out with my RF 800mm f/11 lens and discovered that Electronic full-time MF doesn't work. And, according to the info page, that's true. I tried my RF 24-240mm and it didn't work either. Finally I found the page and tried the RF 100-500mm and it worked... so I wasn't going crazy. 🤪. Note that this is when the auto focus mode is set to servo. They both work when set to one-shot. (And the Electronic full-time MF is set to ON.)
The question is: why? I believe that it is not a physical issue -- since they both work in one-shot mode. I realize that the easy answer is the firmware just doesn't allow it but... bummer!!!!
This really is important when shooting small birds. The auto focus will get "stuck" on a near or far object such as a twig, leaf, or branch and not focus on the bird sometimes -- especially when the bird is in foliage. The easy cure for this is to rotate the focus ring a bit to get the focus off of that object.
I hope Canon will start enabling this feature on all of the lenses.
