Christopher, OF COURSE your 70-200mm will do better thank the 50mm f/.2! It is easier to design sharper, longer focal length lenses of nominal speed than a sharp, ultra-fast normal lens.
Have a look at the MTF charts for these two lenses on the Canon website:
http://www.usa.canon.com/consumer/controll...2&modelid=14259If you have trouble interpreting these charts, please see Michael Reichmann's tutorial at:
http://www.luminous-landscape.com/tutorial...nding-mtf.shtmlThe light black solid line is a graph of high resolution contrast with the lens wide open. Notice that for the 50mm f/1.2 this line STARTS at 50% contrast at the center of the lens and snakes its way down to just 20% at the edges. Even stopped down (represented by the light blue line), this lens dips down from near 90% contrast at the center to 80% toward the edges.
Now look at the MTF chart for the 70-200mm f/4 IS USM. The contrast curves beat the 50mm f/1.2 hands down at both focal length extremes, wide-open or stopped down. Now look back at Canon's sample picture of the girl on the 50mm f/1.2 page. Canon is obviously not trying to emphasize sharpness with this lens.
I believe that the problem here may lie with the buyer's expectation. If I pay $1,300 for a normal lens it better be SHARP, right? Well, not necessarily. What you are paying for here is a very specialized "black hole for light." This is a marvel of optical engineering that is achieved at the expense of trade-offs in contrast/resolution. As such, it seems to me that there is not much use buying the f/1.2 rather than the 50mm f/1.4 other than for an application demanding the f1.2's hyper speed or artsy bokeh. But a close look at the MTF curves shows that even bokeh may be superior on the f1.4.
Having reviewed these charts, I can only imagine that Canon must scramble around to adjust these lenses that are returned to them with "sharpness" complaints or may search through their inventories to find a better-than-normal replacement lens to make a customer happy.
It does pay to study the MTF charts before buying, as I am learning.