Re: Callier effect
Re: Callier effect
- Subject: Re: Callier effect
- From: Mike Strickler <email@hidden>
- Date: Thu, 21 Jul 2005 14:08:23 -0700
Here there is a difference between CCD and drum scanners, the latter
having a collimated source. But this has nothing to do with color
rendition.
On Jul 21, 2005, at 12:30 PM, Mark Rice wrote:
That is exactly the point - scanners do not have a collimated lights
source
-not even drum scanners. Remember the old condenser enlargers we used
to use
for B&W enlarging? They had a collimated light source (different than
the
lens of a drum scanner, and they produced a lot more contrast and
sharpness
than a diffuser enlarger. A scanner is the equivalent of a diffuser
enlarger.
Mark Rice
email@hidden
www.zero1inc.com
I believe you will find Callier Effect only occurs with collimated
light
passed through a silver emulsion. Diffuse light >>does not exhibit
Callier
Effect. The effect on scanning would depend on the light source type
and
optical system (if any) >used to deliver the light to the film.
Scanning B&W silver based film almost certainly does not come out
neutral, because of the Callier effect - the scattering of light due
to solid grains of silver. Conversion to grayscale, via standard
conversion or channel mixing is definitely required.
Mark Rice
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