Photos of autorads

In article <01bbf9a7$e1f7f900$d966c180@ge­neticslab2>,

If you don't have a scanner with a backlight (so you can scan the autorads
in directly) try switching to black and white film.  I use Kodak T-Max
100.  It has much finer grain than color 200 speed film and can be
processed in your own darkroom or by a photo processor.  Since the data
in an autorad is essentially binary (exposed or unexposed silver grain)
any color you get (blue tinted film for example) is an artifact
and if you don't get the color balance right you can distort the appearance
of the output.  Switch to black and white.

--
Tom Thatcher                          | You can give a PC to a Homo habilis,
University of Rochester Cancer Center | and he'll use it, but he'll use it
t @uhura.cc.rochester.edu           | to crack nuts.

I just thought I'd say thanks to all those that wrote in with suggestions.
One note, however, the reason I did not scan the autorads directly is that
they had been hand developed and were a bit dark.  The photos have worked
the best so far, but, I haven't worked with black and white film for 20
years and the turn around at the local photoshop was at least a week, on
the other hand, color can be developed in an hour.  I just need to get off
my butt, and buy some chemicals and locate some instructions.
Again, thanks for the help.
John Korte

In article <5alnq9$ @mserv1.dl.ac.uk>, Wolfgang Schechinger



i agree with Wolfgang.  just scan the autorad in grayscale mode.  if you
have a scanner or software that offers the use of a "filter set" (like the
Relisys modelscombined with Photoshop) and you're using fuji or other film
with a blue tint, set the "filter" to blue and it will completely remove
the original tint of the film without harming the contrast of the bands.
i've also been able to use this to remove sharpie marks from an autorad so
now i mark all my films with blue sharpie (we use fuji film) and all the
marks disappear on the scan.

good luck,

eric

--
Eric C. Anderson
Memorial Sloan-Kettering Cancer Center
Sloan-Kettering Institute
1275 York Ave. Box 470
New York, NY  10028
(212) 639-2977
e-ander @ski.mskcc.org

John, why don't you use a flatbed scanner for that. A 10bit machine (e.g.
the ScanJet 4c from HP, no affil) is good for that. I used to do
densitometry then.

Your blue-green images result probably from the gas discharge lamps that
have a color temp of 3500 K. You may use a correction filter, available at
any foto store or use special film for artificial light.

Wolfgang

-Greetings,
-I have been trying to take photos of autorads to scan into a computer, the
-problem is that my photos are consistently blue-green.  The autorads are
-backlit from a typical light box, photos are taken directly overhead with a
-35mm SLR, with a 90mm macro lens.  I've been using 200 ASA Kodak "Gold"
-film (but I've also tried various color slide film also)  Any idea of what
-filters I could use to curb this?
-Thanks,
-John Korte

In article <01bbf9a7$e1f7f900$d966c180@ge­neticslab2>, "John Korte"

The fluorescent tubes in the light box are the cause of the problem (also
a problem if you take photos in a room lit by fluorescent lamps). Some
possibilities:
1) A good photo store should be able to sell you a conversion filter that
will dampen the blue-green cast.
2) If you are going to scan the pictures into a computer, I should think
you could eliminate the color problems at that level (with Photoshop or
the like).
3)  What is there in an autoradiograph that you couldn't see with black
and white film? I usually use Ilford Pan F.
4) Scan in the autoradiograph itself (in black and white or color--see
above) instead of scanning in the photograph of it.
5) Avoid fluorescent lamps entirely by placing the film on a white sheet
of paper on a repro stand and photographing with incident light (from
above) using tungsten lights (photo floods) with film made for this sort
of lighting (again, a good photo store may be necessary).

--
Ned Mantei
Dept. of Neurobiology, Swiss Federal Institute of Technology
CH-8093 Zurich, Switzerland
man @neuro.biol.ethz.ch   Fax: +41-1-633-1046