Some images crops ,moire and aliasing

David,

The problem is that you look at the image on a device which uses square or rectangular pixels to create the image you see, and you look at it at great magnification.

When the image is printed, it's printed either with continuous tone or with tiny droplets of ink which are round and not rectangular. I've looked at literally hundreds of very large prints from Foveon captures and when properly processed it's nearly impossible to see any of these issues you bring up. All that I see are beautifully sharp and colorful prints which, when compared to the same captures from my CFA cameras are usually superior.

Perhaps printing is not something you particularly care about - some people never print, but I guarantee you that professionals who do look at very large Foveon prints alongside CFA prints of the same scenes by high resolution CFA cameras are nearly always impressed favorably by the Foveon results. This has been demonstrated time and again by reviewers and photographers, yet there are those who seem to either not understand this or can't get past their bias for blur filtering. Leica, Nikon, Kodak and other manufacturers other than Sigma are now realizing this and producing cameras which are not compromised by the decrease in resolution and softening of the images by the AA filter. Do you really believe that they produce these cameras in a vacuum? Do you believe that they do not do their marketing homework before they invest in the production of an instrument to avoid the use of the AA filter?

It's a choice David. It's a choice which many prefer over the aliasing left (and I do know the meaning of the term aliasing) when the AA filter creates "mush" of everything above Nyquist. Yes, the very "filter" which cuts the resolution at Nyquist leaves "nothingness" and that "nothingness" is quite recognizable in significant enlargements as smears of color and grey between visible detail objects. Some may prefer this to "false" detail or as you are more fond of saying "aliasing noise," but many of us don't. So pointing to aliasing and suggesting that you would like to see a Foveon image with an AA filter is counter to that very thing which many of us like about the Foveon sensor. Don't you think that if the image produced by the Foveon were improved by the addition of an AA filter that Foveon would have engineered the sensor that way? Do you really think that they have not tried an AA filter and found it to be detrimental to the image? Give them a little credit. Kodak produced cameras for many years which had removable AA filters which were sold as an expensive (around $2000.00) option. I had one. Most of the time I used the camera without it because the image quality was enhanced.

Please, accept the fact that Sigmas simply do not use AA filters and that the majority of us who use these instruments professionally and for pleasure like it that way and that we are "very" happy with the results we get. When we need or want an AA filter, we reach for our other cameras which have them in abundance.

Best regards,

Lin

--
learntomakeslidshows.net