09-25-2011, 09:19 PM
[quote name='Klaus' timestamp='1316955530' post='11839']
Even assuming that this is the accepted practice these numbers are based on an ideal lens which does not exist, of course.
A real lens is worse than that and combined with the diffraction dampening, which sets in earlier, the "ideal real world" limit is reached (much) earlier.
[/quote]
Yes, indeed, diffraction works at all apertures.
It is just that world class lenses are generally diffraction limited at around F/4, while lesser lenses are diffraction limited at F/5.6, F/8, or even only at F/11. This has a direct impact on the perceived "sharpness" of a lens. Essentially, the larger the aperture at which a lens is diffraction limited, the better its inherent resolution characteristics are.
Kind regards, Wim
Even assuming that this is the accepted practice these numbers are based on an ideal lens which does not exist, of course.
A real lens is worse than that and combined with the diffraction dampening, which sets in earlier, the "ideal real world" limit is reached (much) earlier.
[/quote]
Yes, indeed, diffraction works at all apertures.
It is just that world class lenses are generally diffraction limited at around F/4, while lesser lenses are diffraction limited at F/5.6, F/8, or even only at F/11. This has a direct impact on the perceived "sharpness" of a lens. Essentially, the larger the aperture at which a lens is diffraction limited, the better its inherent resolution characteristics are.
Kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....