05-23-2021 12:43 PM
"... the RF teleconverters a significant step up in image quality over their EF predecessors."
Perhaps so, but I will never know since I have no inclination to try or much less buy one. Even if they were great IQ wise they are still another "thing" you have to deal with. That is my biggest objection to adapters and/or a tel-con.
I have six tel-cons so it is not like I have never been exposed to using them. In the beginning I did use them quite a bit. I found out I didn't like using them so they sit on a shelf in the formerly stop bath stained walls of my ole darkroom.
As far as adapters I have a boat load of them. They are all mostly junk. The one exception is the Ed Mika FD-EF adapter. It works well. I have one mounted on my FD 500mm f8 cat lens. I enjoy playing around with it.
BTW, I do not have any III versions so I have no comment on their IQ ability.