On Mon, 15 Apr 2002 20:30:13 -0500 Laurie Solomon (laurie@advancenet.net)
wrote:
> Tony, what if the "constant colour temp lightsource" is a fluorescent
> discontinuous light source such as what he has said was the light source
> for
> the microscope; will what you suggest still hold?
I have used col neg (Superia and other Fuji mostly) in various
fluorescents and it copes wonderfully with no camera filtration. Unless the
microscope lamp is very weird it should be possible to get good results.
I haven't tried it of course, but I use the eyedroppers as described for
colour correction with just about every colour neg I scan. Usually I use
Vuescan White Balance as a starting point, save in 16bit, then do this in
PS. PS Auto levels is frequently very wrong and I seldom use that.
With crystals, mostly there is going to be a problem finding anything in
the image which is a mid-ish-grey to use the midtone eyedropper on. But
fixed exposure and illuminant remove the variables, so provided a decent
set of corrections can be obtained and saved using an image which does
contain a neutral grey, merely applying the saved levels adjustments should
give a good result with all images from this setup. Close enough that all
that may need doing would be limited to overall gamma, perhaps contrast,
and maybe tweak the hue and saturation a little on some subjects.
Oddly enough, over 30yrs ago I had a maths teacher whose hobby was
photomicroscopy of crystals. He used (Agfa) colour neg and produced awesome
20x16's. It's worth persevering here I think.
Regards
Tony Sleep
http://www.halftone.co.uk - Online portfolio & exhibit; + film scanner info
& comparisons
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