Is the AA filter on the endangered list too?
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From: John Sheehy on 31 Mar 2010 19:39 nospam <nospam(a)nospam.invalid> wrote in news:270320101900106899% nospam(a)nospam.invalid: > In article > <21f2ae10-efbc-4b02-a0c7-0441abf01bec(a)30g2000yqi.googlegroups.com>, > RichA <rander3127(a)gmail.com> wrote: > >> We've seen the before and after shots from cameras on the web. I >> think it is a barrier. > > it's not a barrier. the solution is to use a higher resolution sensor. Yes. When I get my 250MP FF sensor, I don't want the AA filter dropped. I just want its radius small enough to prevent aliasing with sharp, fast lenses. An appropriate AA filter for a 250MP FF would not adversely affect images with higher f-stops; blur (radius) adds in quadrature, and the contribution of the AA would be negligible.
From: John Sheehy on 31 Mar 2010 19:47 RichA <rander3127(a)gmail.com> wrote in news:af3ea6dd-b7e2-430e-bd14- 24f598bf6f01(a)z3g2000yqz.googlegroups.com: > On Mar 27, 5:38�am, Chris Malcolm <c...(a)holyrood.ed.ac.uk> wrote: >>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? > When 24 megapixels with, is like 16 megapixels without. No. 24 "with" has more resolution, but lower *contrast* near the nyquist. 16 "without" is more aliased. Apples and oranges; no simple monolithic metric.
From: David J. Littleboy on 31 Mar 2010 19:58 "John Sheehy" <JPS(a)no.komm> wrote: > RichA <rander3127(a)gmail.com> wrote: > >> On Mar 27, 5:38 am, Chris Malcolm <c...(a)holyrood.ed.ac.uk> wrote: > >>>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? > >> When 24 megapixels with, is like 16 megapixels without. > > No. 24 "with" has more resolution, but lower *contrast* near the nyquist. > 16 "without" is more aliased. Apples and oranges; no simple monolithic > metric. If you actually look at some test charts, and use the (rather reasonable) metric that "to resolve" must mean _to resolve accurately_, then what you see is that 16MP without an AA filter has less resolution than 16MP with an AA filter. (For the obvious reason that aliasing artifacts obscure actual detail.) -- David J. Littleboy Tokyo, Japan
From: nospam on 31 Mar 2010 23:10 In article <Xns9D4CC68E91A16jpsnokomm(a)216.168.3.70>, John Sheehy <JPS(a)no.komm> wrote: > Some people *like* aliasing, because they are optically naive and don't > recognize real detail vs aliased apparent detail. that's sigma's secret sauce. the aliasing doesn't have false colour so they can get away with it (and even claim an anti-alias filter isn't needed). a lot of people fall for it. > Me, personally, I get a very disturbing feeling when looking at aliased > images. Even downsampled, sharp images from the Sigma SD9 give me the > heeby-jeebies. They look like a small nearest-neighbor downsample of a > much larger image; with entire columns and rows of pixels removed, and the > remainder expanding to fill in the gaps. not only are the images aliased like crazy but they're *also* oversharpened. it really hurts.
From: J. Caldwell on 1 Apr 2010 00:39
On Wed, 31 Mar 2010 23:10:56 -0400, nospam <nospam(a)nospam.invalid> wrote: >In article <Xns9D4CC68E91A16jpsnokomm(a)216.168.3.70>, John Sheehy ><JPS(a)no.komm> wrote: > >> Some people *like* aliasing, because they are optically naive and don't >> recognize real detail vs aliased apparent detail. > >that's sigma's secret sauce. the aliasing doesn't have false colour so >they can get away with it (and even claim an anti-alias filter isn't >needed). a lot of people fall for it. > >> Me, personally, I get a very disturbing feeling when looking at aliased >> images. Even downsampled, sharp images from the Sigma SD9 give me the >> heeby-jeebies. They look like a small nearest-neighbor downsample of a >> much larger image; with entire columns and rows of pixels removed, and the >> remainder expanding to fill in the gaps. > >not only are the images aliased like crazy but they're *also* >oversharpened. it really hurts. We're all still waiting for just one image from any camera you've ever touched in life. But we all know better, don't we. You're a pretend-photographer troll who's never touched any real camera in your lifetime. |