Is the AA filter on the endangered list too?
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From: RichA on 27 Mar 2010 03:30 Seems like lighter and lighter AA filters are appearing in certain cameras. The Leica has none. Could it be that this second-last barrier to resolution (the Bayer filter being the last) isn't long for the world?
From: nospam on 27 Mar 2010 03:38 In article <f9d1322f-6524-47fd-b03f-bff99cd582f3(a)o30g2000yqb.googlegroups.com>, RichA <rander3127(a)gmail.com> wrote: > Seems like lighter and lighter AA filters are appearing in certain > cameras. The Leica has none. Could it be that this second-last > barrier to resolution (the Bayer filter being the last) isn't long for > the world? only if someone can prove shannon/nyquist wrong, nor is it a barrier to resolution.
From: Chris Malcolm on 27 Mar 2010 05:38 In rec.photo.digital RichA <rander3127(a)gmail.com> wrote: > Seems like lighter and lighter AA filters are appearing in certain > cameras. The Leica has none. Could it be that this second-last > barrier to resolution (the Bayer filter being the last) isn't long for > the world? Leica's absence of an A filter isn't new. Where are the lighter and lighter ones appearing? And given that every camera maker is producing cameras with larger and larger pixel counts at least every other year, why is the AA filter a barrier to resolution? -- Chris Malcolm
From: nospam on 27 Mar 2010 11:44 In article <OvqMp+BEehrLFwc0(a)kennedym.demon.co.uk>, Kennedy McEwen <rkm(a)nospam.demon.co.uk> wrote: > Not necessarily - if the pixels are small enough to meet the Nyquist > sampling criteria of the optical image then the AA filter is > unnecessary. Since "never" is an extremely long time, this direct > implication of shannon/nyquist will occur long before anyone proves them > wrong. that just makes the lens the anti-alias filter.
From: David J. Littleboy on 27 Mar 2010 16:22
"Kennedy McEwen" <rkm(a)nospam.demon.co.uk> wrote in message news:MIJ8QSAKHmrLFwPt(a)kennedym.demon.co.uk... > In article <270320101144475803%nospam(a)nospam.invalid>, nospam > <nospam(a)nospam.invalid> writes >>In article <OvqMp+BEehrLFwc0(a)kennedym.demon.co.uk>, Kennedy McEwen >><rkm(a)nospam.demon.co.uk> wrote: >> >>> Not necessarily - if the pixels are small enough to meet the Nyquist >>> sampling criteria of the optical image then the AA filter is >>> unnecessary. Since "never" is an extremely long time, this direct >>> implication of shannon/nyquist will occur long before anyone proves them >>> wrong. >> >>that just makes the lens the anti-alias filter. > > Exactly - no need for any additional optical AA filter. But the lens is a really lousy AA filter. When diffraction isn't a problem, the MTF has a very long tail. So you need many times your target resolution, and then that number squared, data points. And does post-demosaicing pixel bining actually work? Don't you lose DR compared to larger pixels? -- David J. Littleboy Tokyo, Japan |