Sensors with Bayer Color Filter Array (CFA) are still the most common, but for a long time not the only ones being used in photo cameras. Since the X-Pro1, which was released in March 2012, Fujifilm incorporates the so called X-Trans sensor with a 6*6 CFA (Bayer sensors have a 2*2 color matrix) in most of its „X“-Series cameras. And even further back, since the SD9, which was released in 2002, Sigma uses a 3-layered sensor called Foveon in all of its compact cameras and DSLRs. And, as it looks at the moment, Canon and Sony are getting ready to say farewell to the good old Bayer design. Canon is supposedly working on a 3-layered sensor, surprisingly similar to the Foveon. Sony is allegedly working on sensors with triangular and hexagonal pixel structure, which have more than the tree standard color channels for red/blue/green. The patent schematics resemble in my opinion the „honeycomb sensor“, with low and high sensitivity pixels, which was used in Fuji S3Pro and S5Pro. That was also an exotic bird, the so called SuperCCD Type II…does anyone remember that sensor?
This begs the question, will Bayer sensors soon be a thing of the past? Well, it goes without saying that these sensors are still a great compromise between resolution and sensitivity/noise performance. They, however, are not exactly outstanding in regards to per pixel resolution (or as some like to call it “per pixel sharpness”) and efficient utilization of optics. The question is not how many megapixels Bayer sensors will be able to reach eventually, but rather whether at one point optics will fall behind physics. For example, Foveon with 15MP in APS-C format can already outresolve many full frame Bayer sensors with in some cases well above 20MP and a 2.6 times larger surface area. Let’s imagine what would happen if one company with more resources would refine the Foveon or if Sigma would invest the profits made with Global Vision lenses into their sensor R&D. A game of make-believe, just for fun: 15MP * 2.6 = 39MP, plus a few enhancements to improve noise performance. I seriously wonder what Bayer sensor could keep pace with such a „monster“?