Ever looked at the specs for a Digital Camera (video or photo) and see it talk about “4:2:2” or “4:1:1” sensors, and wondered what that meant?  Well, John Galt has a fantastic article over at CreativeCow about what this means, how it translates to the older notion of video footage and sensors, and why it does and doesn’t matter.

For motion picture camera sensors, the word “pixel” is kind of complicated. In the old days, there was a one-to-one relationship between photosites and pixels. Any of the high-end high definition video cameras, they had 3 sensors: one 1 red, a green and a blue photosite to create 1 RGB pixel.

But what we have seen particularly with these Bayer pattern cameras is that they are basically sub-sampled chroma cameras. In other words they have half the number of color pixels as they do luminance And the luminance is what they call green typically. So what happens is you have two green photo sites for every red and blue.

Towards the end it gets into 4k (IMAX) frame sizes and how they aren’t truly 4K.

via The Truth About 2K, 4K and The Future of Pixels – Creative COW.