"Pat" <groups.DeleteThis@artisticphotography.us> wrote in message
news:1184260472.765929.184620@22g2000hsm.googlegroups.com...
[re wet scanning]
> If you send it out to someone with a wet scanner, they will know how
> to handle the photo in a non-destructive manner (I hope).
>
> Wet scanning a very effective.
Yes, hopefully. I've done it myself, most recently on a tintype that had
incredible amounts of detail, but with the surface so roughened with time
that very little it was visible. The result was stunning - a tiny 1x1 inch
image that could be blown up to a serviceable 5x7. In this case, I use pure
grain alcohol that evaporated in a matter of seconds, to minimize any chance
of rusting the iron substrate under the emulsion.
But in dealing with old photographs, I think we have a duty of preservation,
and not simply reproduction. For paper prints, there are any number of
dangers that can happen when water, alcohol, or oil are used for scanning an
image. For a print, there are the additional problems related to the paper
itself: drying the print, migration of material in the paper, and restoring
it's original appearance.
1) the emulsion itself may physically peel away from the paper, destroying
the print
2) if the image was incompletely washed or fixed, portions of the emulsion
may be soluble in water
3) iron impurities and other undesirable chemicals in the emulsion may
migrate when wet, causing later changes in the image appearance.
4) markings on the back of the image may soak through.
5) the surface sheen of the emulsion may change
6) if a print dryer is used to restore the original convex shape of the
print, the softened emulsion may crack while drying, and/or stick and come
off
All of the above problems may show up immediately, or may take years to
happen.
If you are lucky, and none of the above are a problem, you will be faced
with the problem that after drying the paper will curl toward the emulsion
side - even with proper drying technique, there is no guarantee of restoring
the print to its original appearance.
These are obviously important prints, or we would not be taking this amount
of trouble to scan them. Even if you get a good scanned image, for many of
us damaging the original is too high a price to pay, particularly when there
are non-destructive alternatives that can be tried first.
Furthermore, scanner technology may improve in the future. For example,
imagine a version of Digital ICE for print scanners that removes surface
texture. Using such a device, it might be possible for someone a few years
from now to get a batter scan than is possible today even with soaking.
This makes it even more important not to damage or otherwise modify the
originals. Archaeologists are aware of this, and often leave sections of a
site untouched, anticipating future improvements in technology and
technique. We should do likewise with our photographic prints and
negatives.
BTW - for more material on scanning old images, and potential problems such
as those mentioned above, I recommend my friend Ctein's "Digital Restoration
From Start to Finish".
--
Mike Russell -
www.curvemeister.com >> Stay informed about: scanning textured photo?