Digital BW, The Print

Hi Truman,

> Why do you say red has " the highest energy of the three." I would
> expect that would depend on the spectrum of the light source and the
> bandwidth of the filters. Please elaborate.

The light source is a white light, and has all colors, it is filtered with
"a" color filter, and only light of the color of that filter reaches that
sensor.  Red just simply has the highest energy of the three, as far as the
CCD "sees" it.  It has to do with the quantum efficiency of the CCD (how the
CCD reacts to different spectrums of light).  Red typically has up to an %80
quantum efficiency.  Blue and green only top out at about 60% right at their
peak sensitivity.  Red stays quite high for almost the full width of its
sensitivity.  Also, the spectral width of red is very very high, from 575nm
to 850+ nm.  Blue is 375nm - 550nm and green 450nm - 625nm.

Bring a color image into PS and thumb through the channels (CTL 1, 2 or 3
for RGB, and CTL ~ for all), and you'll see that red is easily the fuzziest,
blue and green are very image dependant as to which is better...

Regards,

Austin