Originally posted by Wild Mark Would it be fair to say that the legacy FF lenses will actually perform better, or to their "lines per mm" specification, on an actual FF sensor when compared to the APS-C sensor?
No not necissarily. It comes down to the airy disks of the lens and whether they correspond to the pixel pitch.
Originally posted by Wild Mark DA lenses are optimised for the smaller sensor and in so doing might pack more "lines per mm" specification than their FF cousins (by design). That is, the FF legacy lenses were not designed for the camera digital enlargement that increases the APS-C image size to a FF equivalence (is this correct this statement?).
DA lens are made with better materials than many older legacy lenses, and are projecting an image circle to suit the crop sensor rather than that of the 35mm size. The airy disks of the DA lenses correspond to the pixel pitch. There is no digital enlargement, the statement is incorrect.
Spiros Heniadis explains airy disks here:
The situation with Canon users regrading using FF lenses on crop or even on the 50mp 5D, is that Canon recommends certain lenses to suit either sized sensor.
What is probably "doing your head in" is that the Sony Bionz image processing firmware is removing the purple fringing from the images. They expected folks would use old lenses, so they made CA removal possible. Turn off CA removal and see what you get.
I have a Fujifilm camera that removes the red veins from eye's automatically.
I'd say its just Bionz removing CA's and not the supposed miracle of FF.