Quote Originally Posted by JJphoto View Post
for 70-300mmL, you will lose AF at 300mm with the TC.
I was actually referring to the 300mm with the 1.4x III not being as good as the 400mm F/5.6. What I meant to say about the 70-300mm L is he has 300mm covered, in that regard the idea doesn't make sense as he is duplicating the reach he already has. I don't think the 70-300mm L with a 1.4x would be a good option.