Quote Originally Posted by HDNitehawk


The comparison between the two seem to suggest a fair amount of improvement in the midframe.


At f/8, that's true, but performance at f/5.6 is more important, IMHO. Plus, even at f/8 the center is slightly worse, and that's also more important if you still have to crop a lot.


Quote Originally Posted by HDNitehawk
With the promise in extenders improvement that is shown in the theoretical charts on the 500mm and 600mm,

I think this new 400mm f/2.8 shows Canon's MTF charts mix a lot of fiction with fact. They indicate that the 400mm f/2.8 II with 2X has the same contrast as the 400mm f/2.8 I with *no* teleconverter, at every image height except the corners. Maybe that's true that super low resolution Canon measures (30 lp/mm) for their charts, but it sure is wrong at the resolution that matters to me.


So far, my view on the new lens is that the primary benefit is weight and non-TC performance.