Originally posted by Rondec Certainly the DFA and DA * zooms are sharp stopped down a stop, the same as most primes. Size and large resistance are the biggest two differences to me. Compare the DA *200 to the DFA * 70-200 and the difference is huge.
Browsing in LensTip dot com, a while ago, I observed that primes usually can resolve >50 lpmm in the center, while zooms don't peak that high, usually around 40lpmm. Zoom have flattened responses versus aperture. A good hint that MTF response curves can be compared is that MTF of both primes and zooms join the same point once diffraction kicks in at f16, f22, then the difference between prime and zoom is negligible.