Have any of you tried the above combo?
I currently have the Kenko 2x Pro 300 DG (red dot) which is okay for the money (cost about £110) but images aren't quite as crisp as I'd like so I don't use it that often. Can any of you comment on the sharpness of the 300mm with the mk3 converter or post images? Also, is the AF speed still acceptable to you? I'd be using the combo for airshows or birds in flight etc.
Whilst I'd rather have the 500mm f4, I'm thinking of the cheaper option first! If I got the mk3 TC I'd probably also buy a Wimberly Gimbal head too.
Any suggestions are appreciated.
Body is a 5D3.