I just realized my Tokina 12-24 showed inconsistent exposure: At the wide-end, it underexposed by about -0.5ev at smaller apertures (e.g. f/16). i.e. If I set it to 12mm, set the camera (D70) to A mode and spot meter, take a shot of a graycard @ f/4 and then take another shot @ f/16, the f/16...