I've currently been using the Canon 55-250 on the T3i camera and while the lens does well at times, I have found the autofocus performance and overall image quality lacking other times.


I've considered looking at the Canon EF 200mm f/2.8 to improve my images. I'm confident that as is the lens would be excellent for sports, near wild life (I've set up a bird feeder) and some other general use. How does it take to converters especially on a Rebel body? I see the ISO crops on this site and generally they look good even with the 2X extender used.


Does the autofocus suffer with the 1.4X or 2X TCs to the point where it is as slow or worse than my 55-250? Does the contrast with the 2X suffer to the point the images will still be lacking?


Would it be wiser to just save up and get the 100-400 L? It is quite a large lens compared to anything I'm using now and especially for a Rebel body.


Dave Throgmartin