[QUOTE="Floyd L. Davidson"]\nIt's the other way around.\n\nDiffraction is an effect that happens when light passes\nan edge, and the smaller an aperture is the larger the\npercentage of light going through is close to an edge.\nThe center of a large aperture is not anywhere near an\nedge, but even the center of a small aperture is close\nto the edge.\n\nSo large apertures for any given focal length have less\ndiffraction as a percentage of all light that goes\nthrough the lens.\n\nAn f/64 aperture on a 300mm lens passes a lot of light\nthat is not affected by diffraction. But an f/8\naperture on a 3mm lens does not pass any light that is\nnot affected. The 300mm f/64 might work well with a\nlarge format, but the 3mm f/8 requires a very small\nsensor.\n[/QUOTE]\n\nI guess, this is where I get lost...\n\nSmaller sensored cams (with smaller lenses) don't seem to be affected as\nmuch by diffraction limiting but, if I understand you properly, that's\nbecause those cams also have larger apertures (usually larger than or equal\nto f8.\n\nIf those smaller sensored cams came with smaller apertures, let's say f22 or\nhigher, then their image quality would be degraded by diffraction limiting\nmore so than DSLR or larger format cameras?\n\n\n[QUOTE]\nExactly. And that is because they used large sheet film, and long lenses.\n\nTry f/64 on a full frame 35mm sized sensor and the blurring of diffraction\nwill be very significant.[/QUOTE]\n\nIf I understand you, diffraction limiting at any aperture other than wide\nopen is caused by the diameter of the aperture blades. At wide open, the\ndiffraction would be caused by the lens' edge.\n\nI take it that the design of some apetures might cause more or less\ndiffraction limiting depending on the blade design / configuration?\n\nThanks for the info, Floyd; it's greatly appreciated.