Re: Black and white negative scanning
Re: Black and white negative scanning
- Subject: Re: Black and white negative scanning
- From: Chris Protopapas <email@hidden>
- Date: Tue, 13 Nov 2007 15:38:12 -0500
Generally speaking it is impossible to profile negative scans. The
reasons are fairly simple: color management, the creation of
profiles, needs a fixed target to work on. Transparencies and
reflective art fits that definition, but negatives generally do not.
The negative, whether B&W or color, is not the final image, but
merely a means to an end. Negatives will often vary enormously in
exposure and contrast. This is much worse with color negatives, but
B&W are subject to the same variation. In the same fashion that a
printer cannot be successfully profiled if it is constantly drifting,
negatives cannot be profiled, except in an extremely loose way. For
example, I use my drum scanner's transparency setting to scan B&W
negatives, and then assign the transparency profile (in RGB) to yield
a negative image which can then be inverted to produce a positive
image, but the role of the scanner profile is not essential; it's
just part of my workflow. That has more to do with my 1997 drum
scanner's software being unable to easily produce a positive scan
than anything else. The software for an Epson scanner should be able
to produce decent B&W scans. First set your black point in the DMax
of the negative; that will give you a black that cannot be lighter
than anything in the live image. This is very important, but you will
soon notice that different negatives will yield different results.
This is because there is no neccesary relationship between the
unexposed film and the shadow areas of your image, unlike a properly
exposed positive, where the DMax is very close to a true black in the
live image. A negative can be overexposed, still be printable, but
the shadow areas will have much more exposure than the DMax. This is
one reason why negatives cannot be profiled; the black point is not
consistent, and constistent conditions are the pre-condition for
color management. Diffrences in processing, and different film
stocks, will affect the contrast of the image differently, again
making profiling impossible. That said, scanning B&W negatives is
easier than scanning color negatives, where there are even more
variables. In reference to your other questions, 16-bit is a good
thing if your original scan is very flat, and you need to do major
work in Photoshop. As far as grayscale profiles, I use 20% dot gain,
but other profiles will work as well. It dosn't hurt to provide a
tagged file to a printer.
Chris Protopapas
************
email@hidden
Fuel Digital Inc.
902 Broadway, 11th Floor
New York, NY 10010
P 212-564-4646 F 212-564-2131
www.fueldigitalinc.com
Message: 14
Date: Tue, 13 Nov 2007 13:51:56 +0100
From: Ludovico Fischer <email@hidden>
Subject: Black and white negative scanning
To: ColorSync List <email@hidden>
Message-ID: <1194958316.5630.20.camel@gogo>
Content-Type: text/plain
Hello. I want to scan some black and white film negatives with a epson
v700 flatbed, for archival purpose.I imagine it would be practical to
scan them as 16 bit grayscale TIFF, as the files will be smaller and
there is no need for tinting or such effects. I am asking myself:
-is there a way to profile the scanner for such media? Given the nature
of negatives, are there benefits in doing so? Is there a benefit, for
example, in using a profile made with a IT8 target printed on reversal
film ?
- What do I use as a working space profile? I've heard about 'grayscale
icc profiles', but I can't find much information (except stuff refering
to Photoshop 5). What are these? Or do I use a profile such as AdobeRGB?
-same thing for final output. Is there a benefit in attaching an icc
profile to a grayscale image for viewing in color managed applications?
Would that be a regular color profile or one of these 'grayscale
profiles'? And if I print such an image? Do the printers expect to have
an icc profile with a grayscale image?
I'm sorry if the questions are really off the mark. Thank you,
Ludovico Fischer
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