Well, the diffraction limit for a 14mm lens, without considering sensor pixel pitch at all, is around f/6.3 or so. I always consider lens diffraction limits to be when the iris gets down to around 2mm in size, whatever f/number that works out to be for a given focal length. Some lenses are more sensitive than others due to placement of the iris in the light path.
I haven't seen the formulae that factor in pixel pitch and aliasing. Godfrey On Dec 14, 2006, at 6:14 PM, Digital Image Studio wrote: > Does anyone want to have a stab at estimating the practical > diffraction limit for the K10D? My *ist D resolution seemed drop off > from about f16, so I assume for a Bayer filtered sensor the practical > limit would be something like twice the airy disc diameter plus a bit > to account for the AA filter? > > The *ist D sensor has 7.8µm square photosites so the aperture to > produce an airy disc of twice that is f11 plus one stop fudge. Given > that the K10D sensor has 6.05µm square photosites applying the similar > factors would yield a drop in resolution after about f13. > > I haven't done any serious comparisons as yet but I'll be keen to see > if the theory fits the practical. > > If you think it's all a crock then you are quite entitled to your > opinion :-) -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
