Does anyone here know if the Tokina 12-24 4, 16-50 2.8 and 50-135 2.8 are much different from the Pentax DA* versions? I have both a Pentax and Nikon camera and would like to own these lenses among others in either range. I want to get rid of one because it is going to cost to much to support both systems; I may skip the Tokina 16-50 2.8 and get the Nikkor 17-55 2.8 instead if I stay with Nikon. Anyone have any suggestions?
the difference between the Pentax and Tokina lenses are in the mechanicals - the lens focus/zoom mechanism and the housing. optically and coating-wise, they are supposed to be identical. the Nikkor 17-55 is excellent except for flare. i don't care about distortion so i don't know how it measures up in that respect. CA, sharpness, and falloff at small apertures are mostly all i care about. i probably will get all the DA* lenses. i may get the Tokina 50-135 for Nikon, but that depends on my performance testing.
