Today, Chatty taught me that camera sensors have 4 photosites, 1 red, 1 blue and 2 green. This was invented by Bryce Bayer in 1975 and was patented in 1976 as "Color imaging array".
The second Green ...
Check out Fujifilm's X-Trans sensor which uses a more complex 6×6 repeating pattern. There’s also the older Foveon X3 sensor used by some Sigma cameras. Foveon captures RGB information differently and doesn't use a Bayer or X-Trans color filter array at all.
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