| Latest Review Posted | Tamron-F 1.4X Pz-AF MC4
Excellent test shot results. A+ performance. :D
I purchased this tele-converter primarily for use on my SMC Pentax-F 1:4.5 300mm ED(IF) lens (one of Pentax's sharpest) and that is what I did most of the testing with. Using my K10D shooting DNG raw files at ISO 200, comparison shots of a highly detailed, multi-textured, relatively flat field subject were taken with lens tripod mounted, aperture wide open at F/4.5, with and without the Tamron tele-converter mounted, same field of view (tripod was moved forward from 300 + tele-converter position for same field of view with 300mm lens only). Shots, when compared side by side on Viewsonic Graphics Series G90fB CRT monitor at 1280 x 1024 screen resolution, at 100% and 200% image resolution, showed no discernible sharpness or detail degradation, on center or at the edges of the image. The only discernible difference was a VERY slight red shift, indicated by just a few points increase in the red channel, and a very minor decrease in contrast.
To see any degradation in detail and sharpness I had to shoot with my K20D (DNG raw, 4672 x 3104 pixels, ISO 200). Only then, at 100% side by side comparison viewing of the images could I begin to detect any difference, looking hard. It was only at 200% that an untrained eye, looking for differences, would likely see any, and those very minor. Without direct side by side comparison the incremental red shift and tiny decrease in contrast would not be apparent.
This is exceptional perform... |
