Is MTF/50 a good way to rate lenses? I have been in the market for quite some time for a couple of lenses. I have clearly settled on the 10-22 as I really need something wider but continue to vacillate between two others. I have read just about every review here and other places and leave more confused than ever. Some are clear like comparing the 18-55 kit to the 17-55 f/2.8. The 17-55 beats the 18-55 in Vignette, chromatic aberration, and MTF/50. But other lenses are not so clear. For instance the 70-300 IS and the 100-400 IS and the 400 prime. When I compare the stats of the 70-300 against the 100-400 they are pretty much dead with a slight advantage in MTF/50 to the 70-300, even yet most say that the 100-400 will just blow away the 70-300. The picture gets even fuzzier with the 400 prime. It’s MTF/50 is notably less. So, what other measure can one use? Is it all subjective? Is word of mouth or trial and error the best we got?
