Digital BW, The Print

Paul D. DeRocco writes:

> I'm like to know more precisely what you mean by "color resolution" and
> "creamy pastels".

Color resolution means the finest details that can be resolved in an
isoluminant image, that is, the finest _color_ differences that can be
resolved.

Only one out of every four pixels in a digicam image has any blue
information; the same is true for red.  Only every other pixel has green
information.  All the rest is an educated guess added by the camera
software (or by subsequent processing of a raw image).

This means that one- or two-pixel details in red and blue can't be
resolved properly by a digicam, since only every fourth pixel even
captures red or blue to begin with.  One effect of this is that noise
seems to be reduced, because one pixel is being smeared over four
pixels.

> The former sounds like something that could have a formal
> definition, but the latter sounds like something subjective that doesn't
> describe anything I've seen.

"Creamy pastel" is just another way of saying a limited gamut and
limited saturation.  Again, this is a consequence of the use of a matrix
filter over a single sensor.  It would not be a problem with three
separate CCDs capturing every primary color for every pixel, or the
equivalent (like a Foveon, if it were ever perfected).