- May 29, 2019
Yes and no. That would be a way to make an RF compatible lens, but a true RF lens would take advantage of the high bandwidth RF connectivity and at a minimum would have a lot of new electronics and probably a different IS motor as well. The RF system was designed to be fully compatible with EF lenses, native RF lenses have more features (some of which we haven't even experienced yet with current bodies).I'd say after 6 weeks of testing a 400mm f2.8 IS III that the adapter to body connection was a little wobbly. Not enough to harm images, but enough to give a feeling that a true RF build would be worth the wait.
No quarrel with your point, and as I've posted elsewhere, an RF version of the 400 IS III is nothing more than an summer engineering intern modifying the rear housing and using flex circuits an inch longer.