> (Yes, it's 3 - the luminance sensors (the 'rods') have the same
> sensitivity as the 'green' channel 'cones')
Not quite, they respond to a wider spectrum then the green sensors.
Though they are highly sensitive to green, they respond to most all
of the visible color range. I think.
(Actually, after saying that I'm not really sure how wide the spectral
response is for luminance, but I do know that luminance calculations
certainly all include some red and blue, and I presume there is a
psychological/physiological reason for that.)
> Back to scanning - if you need to get all the info that is in a
> photograph ABOUT THE ORIGINAL SCENE, a three channel scanner is
> enough, because the original photo process has already reduced it to 3
But do the spectra of those three channels cause the RGB sensors in
your scanner to respond similarly? That's a question for a photography
expert, I think. All I know is that it can be a real chore finding the
right combination of light, sensor and filters just to get white paper
to come out right. Been there, struggled with that.
-- Steve Williams "The woods are lovely, dark and deep. firstname.lastname@example.org But I have promises to keep, email@example.com and lines to code before I sleep, http://www.picturel.com And lines to code before I sleep."
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This archive was generated by hypermail 2b29 : Tue Dec 12 2000 - 13:18:16 PST