Originally posted by civiletti According to PhotoZone tests, the FA77 is not even close to the DA70 in wide-open resolution:
In fact, border resolution of the DA70 is significantly higher at f2.4 than the FA77's at f2.8.
But in general usage with this focal length, you don't usually care about border resolution at the higher apertures. When you need across-the-frame sharpness (no subject isolation,), you are usually stopping down - and at f/5.6, the 77ltd has matched the 70ltd across the frame, and beaten it by f/8.
At f/2.8, the first common aperture shared in those charts, the 77ltd is sharper in the center - at f/2.8 and larger, you're usually shooting for subject isolation, in which case the less-resolved edges actually add to the 'pop' and 3-D effect.