I think we're thinking about slightly different things. I agree with what you say about visible moire, but I'm also thinking about non-moire aliasing artifacts. These still represent (in my mind at least) a corruption of the image, but they are not easily visible in the image (without comparison to reality which people aren't usually able to do when looking at a photo) and therefore not aesthetically objectionable. One might say that if they aren't visible they don't really matter, and that's fine. I'm just pointing out that some of the perceived detail increase you get from omitting the AA filter isn't accurate/real, but I realize that some may be willing to pay that price for sharper looking images.
If the image projected on the sensor (including lens imperfections, diffraction, camera shake during the exposure, etc.) has the right amount of blur to be Nyquist sampled by the pixel pitch then you won't get aliasing, and adding an AA filter might unnecessarily decrease the resolution by something like sqrt(2). So in that case there would be no advantage to an AA filter and for all I know that may be a common situation. Personally, I think I would rather give up a little resolution to know that I won't be adding artifacts to the image (but I've never used an AA filter-free camera so this is all theory), so I hope I'll continue to have that choice as with the K-5 II and IIs. Nothing in here will be news to you, but I found this recently (via PetaPixel) and thought it was pretty good (though admittedly it approaches from the "all artifacts are bad even if you can't see them" point of view): http://www.martin-doppelbauer.de/foto/tippstricks/aliasfilter/index.html P.S. For the record, if anybody wants to give me a Leica with no AA filter I will not turn it down! On Thu, Feb 21, 2013 at 5:48 PM, Matthew Hunt <[email protected]> wrote: > On Thu, Feb 21, 2013 at 5:30 PM, Bryan Jacoby <[email protected]> wrote: > >> I agree that it will be a practical problem very rarely given the >> pixel pitch. But I think that is another way of saying that the >> sensor is over-resolving what the lens, etc. can do. Which I think is >> another way of saying what you're mostly getting is bigger files, not >> more real detail in the images. > > Well, I don't think that's quite right... with good lenses at a sharp > aperture and careful technique, I think you can make use of the sensor > resolution and achieve high detail. But to provoke moire, you need a > pattern with just the right spatial frequency in the same part of the > image where you're achieving that sharpness. I think it's the > combination of those two factors that makes it so rare in practice, > rather than it just being a matter of the sensor always over-resolving > the optics. > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
