I think there is some good info on the answers on this page (be sure to click the "4 more answers" link: http://photo.stackexchange.com/questions/22758/how-do-digital-sensors-that-capture-one-color-at-each-photosite-compare-to-senso
I think the most interesting comment on the above page is the following: QUOTE: What you actually want is to cram so many megapixels in the sensor that you can do away with the AA filter, and bin different coloured pixels together if necessary to get Foveon style dense colour sampling, but without the low light penalty or huge cost. With 24MP crop sensors arriving that day is close! CLOSE QUOTE: I have never seen those two things connected before (cramming megapixels previously considered a bad thing, as far as noise is concerned). That seems to be part of what Pentax has made work on the Q. The pixel pitch is incredibly small, but they have been able to eliminate the AA filter. That also seems to be the direction that Nikon has gone with the D800E. They've gone to way more megapixels than Canon, but that has allowed them to eliminate the AA filter. I would imagine that this approach means that you are giving up some high ISO performance, so you have to pick your priorities, or have different cameras for different priorities. Related to the bit depth discussion, I also found this interesting: QUOTE: Since 12-bit data has 4,096 tonal levels and 14-bit data has 16,384 tonal levels, one might expect to see smoother tonal transitions and less possibility of posterization with 14-bit capture, both of which would result in higher image quality. However, this is currently not the case for most 14-bit cameras due to the fact that digital noise overwhelms the extra bit depth. Slicing the data more finely than the level of noise means that the extra bit depth doesn't contribute to image quality. Another factor that keeps us from realizing extra image quality from a 14-bit sensor as opposed to a 12-bit sensor is that most current DSLR cameras have less than 12 stops of dynamic range. Unfortunately, this makes the extra bit depth superfluous data. There are some exceptions. Fuji cameras employ two sets of pixels of differing sensitivity that allow for spanning more than 13 stops, so 14-bit depth is useful in that case. The latest Sony sensors, used in Nikon, Pentax and Sony cameras, have very low noise levels and high dynamic range and so are close to being able to generate genuinely useful 14-bit data. As sensor technology continues to evolve, lower noise levels and greater dynamic range promise to make high bit depth capture a useful feature in future cameras. CLOSE QUOTE Source: http://dpbestflow.org/camera/sensor It is worth noting that Dx0Mark has the K-5 with a Dynamic Range of 14.1 EVs. The K-01 (also 16MP but 12 bit, not 14) has a Dynamic Range of only 12.9 EVs (a significant difference, IMHO). Back to the Foveon... Dx0Mark does not even evaluate them saying (in Sept. 2010): "We would love to add cameras featuring Foveon sensors such as SD14/15, however the specific sensor structure and file format requires some changes on the site to enable fair comparison with Bayer-type sensors. We may then consider doing it at some point but unfortunately we can't give any date." Source: http://forum-test.dxomark.com/index.php?topic=296.0 And SD14 owner made some measurements and comparisons, which you can see in the final comment on this page: http://forum-test.dxomark.com/index.php?topic=296.0 His comments also address the color noise problem apparently inherent to the Foveon design. Between that problem and the apparently increased costs associated with producing Foveon sensors, I think they will be limited to Sigmas only and be a niche product for people who only want to work at low ISOs. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
