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Musings about Photography and the Science behind it


We’ve seen how humans perceive color in daylight as a result of three types of photoreceptors in the retina called cones that absorb wavelengths of light from the scene with different sensitivities to the arriving spectrum.

Figure 1.  Quantitative Color Science.

A photographic digital imager attempts to mimic the workings of cones in the retina by having different color filters arranged in an array on top of its photoreceptors, which we normally call pixels.  In a Bayer configuration there are three filters named for the predominant wavelengths that each lets through (red, green and blue) arranged in quartets such as shown below:

Figure 2.  Bayer Color Filter Array: RGGB  layout.  Image under license from Cburnett, pixels shifted and text added.

It is the quality of the filters in the array (CFA) that determines how accurately a digital camera is able to capture color information from the scene.  So what are the characteristics of better CFAs and can perfection be achieved?  In this article I will pick up the discussion where it was last left off and, ignoring noise, attempt to answer this  question using CIE conventions, in the process gaining insight on the role of the compromise color matrix and developing a method to visualize its effects[1]. (read more…)

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Musings about Photography