Re: Viewing the Grain-Mike K. ( digest 1519)

[P3D Bob Howard <bobh@xxxxxxxxxxxxxxxxxxxx>]

RE: In discussing digital camera resolution, Mike K. is taken by the
fact that film grain is equated to a molecule, done to emphrasize how
hard it will be to make a CCD mosiac as small. He also says Dr. T's
viewers are WOW since you can see the 'molecular sized grain'.
This made me smile because everyone is forgetting that in transparency
film while the image is captured by a silver emulsion and the dye image
is developed after reexposure (to get the positive), the effect is that
the "grain" we see in such films is the SPACES between grain in the
original. This is also why color prints from neg film are so fine
grained, the three layers grain pattern is random and when stacked don't
have much space between to show as grain. All color films except
Kodachrome (and Polaroid instant) are Agfacolor type wherein the dye
couplers are in the film. In Kodachrome they are added in three color
processing/exposure steps. So the fact that the dye packets take space
and when exhausted make 'holes" explains why Kodachrome is so fined
grained..it isn't pockmarked by the old dye packet spaces. So it is
really remarkable that they have gotten the E-6 processed film so good.
 As to resolution. I have read that the best $20,000 digital CAMERA is
not quite on a par with a 110 negative. Also these cameras until
recently had a CCD area less that the full frame 35mm area, so the focal
length of 50mm was now a bit telephoto, and wide angles less wideangle.
This to point out why PHOTO-CD captured film image is still a better
digital image than the existing cameras. BobH


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