Originally posted by dlh And, apropos of that, I get all my lenses in FF (one exception DA* 55, which works pretty well on the K-1), since they will do well on APS-C (and I would say, generally outperform the native APS-C lenses) .
You do get less vignetting and more uniform performance across the frame; the counterpart, of course, is heavier weight and larger size. The (APS-C) 50-135/2.8 is substantially smaller and lighter than any FF 70-200/2.8.
Then again, all but one of the lenses I used in my K-7 are FF (save for the Tamron 17-50/2.8, which was frankly unbeatable as walkaround zoom unless I were to drop some serious cash).