Today’s Question: In your answer about TIFF versus raw captures you said that “most raw captures don’t contain full color information for each pixel”. Wouldn’t this be true of all raw captures since that’s what makes a raw capture “raw”?
Tim’s Quick Answer: While most digital camera image sensors only capture a single color for each pixel, not all sensors have this limit. For example, the Foveon X3 sensor captures full color for each pixel.
More Detail: Most camera image sensors use a Bayer pattern array, where out of every four pixels two record green light, one records red light, and one records blue light. Other image sensors use a variation on this concept. But most only record one color value (red, green, or blue) for each pixel. Software then processes this information to calculate the “missing” color values for each pixel to generate the full-color image.
This issue is generally referred to as the image being mosaiced, meaning it contains a mosaic of different values that don’t represent complete image data. This mosaiced attribute is what we generally consider to represent a raw capture.
However, there is at least one exception that has made it into production cameras. That exception is the Foveon X3 sensor, which uses a layered approach to record full color information for all pixels on the sensor.
While the technology and concept of the Foveon X3 sensor is impressive, that hasn’t translated into wide adoption. The company that created the Foveon sensor was acquired by Sigma a number of years ago, and the sensor has only been available in Sigma cameras. The Sigma cameras haven’t seen wide adoption.
So, the vast majority of cameras don’t capture full color information for all pixels, but there are exceptions.