Bayer Sensors...Patented 1976...but things have changed a bit...

If you spend any time working with television or feature or high end television spot production, you've probably heard at least one person express wonder or disdain, or perhaps complete faith or doubt in the relative merit of a Bayer Pattern sensor.

The original patent, granted on July 20, 1976, has the sensor primarily as a Y'CC (color difference) sensor with the green photosites shown here being Y' and the red and blue photosites being "C1" and "C2" (as opposed to naming a specific color difference structure).

(image is courtesy of Wikimedia)

However, Bryce Bayer changed the proposed sensor layout for an RGB implementation in the patent. Today, most well known Bayer implementations in the 'digital cinema' technology area (RED, Silicon Imaging, etc.) are RGB, and photosites are distributed as illustrated in the first visual. However, the original vision for a Bayer pattern RGB sensor in the patent was actually what you see here:

You'll notice that blue is sampled far less... Apparently the arrangement was meant to mimic human visual acuity, which is of course sensitive most to green, less to red and least to blue. The sensor's layout would have spatially sampled 50% Green, 37.5% Red, 12.5% Blue.

It would've been curious to see how such a sensor performed. Though it would've been maddening to develop a low pass filter for it...

(I don't know of any implementations of this highly asymmetrical system, but I don't work much with still imaging or highly specific industrial applications...if you know of one, please add it in the comments.)

Original Bayer sensor patent #3,971,065.


TimK