Quad Bayer vs Quad Pixel AF: what they are, how they work and how they differ

The Olympus OM-1's sensor has 80 million photodiodes, which are used to deliver 20MP images and across-the-sensor X-type phase detection. This sometimes gets mistakenly described as a Quad Bayer design. That's not the case though, so we're going to take a look at how these two different systems work, how they differ, and contemplate why neither of the ILCs known to use Quad Bayer sensors make that detail public. What is Quad Bayer? Sony Semiconductor has developed a technology called Quad Bayer,...