Have I bought the Tokina 11-16 mm for my Canon EOS 450D. An absolutely great lens !! Sharp and contrasty in all focal areas, optimum aperture is probably at 5.6, but even with 2.8 or 4 absolutely great results. The chromatic aberrations at the edge of the image at 100%, I can get over this -crop. Super processing, super sun visor, but also difficult and high quality. Focal range is not great, but really usable in the highest quality. In full-frame only 16 mm available with edge drop. Compared with the Sigma 11-22 significantly more sharpness and contrast, but at the same settings less depth of field ?! Tokina !, please builds as a lens with 16-28 mm in this quality for the full-size !!