Originally Posted by
xpatUSA
Just to be clear, there is no "color filter" per se - unlike the color filter array that sits on top of non-Foveon sensors. Each of the three Foveon layers responds to the whole visible light spectrum (say 400-700nm), albeit non-linearly. The "RGB" designations refer to the point of maximum QE for each layer. Non-intuitively, the lower layer has the highest QE of the three layers, in spite of what many think.
Please pardon the clarification.
I think that @bingo would be better served if we all refrain from giving our own versions of "how the Foveon works" and instead address his/her questions as simply as possible. Should shorten this thread quite a bit because, personally, I could go on about loose terminology and minor technical points for ever ad nauseam.