From: Robert W. Schramm (schrammrus@hotmail.com)
Date: 06/04/00-07:34:10 AM Z
I don't know how many folks on this list use 35 mm SS film tanks
with plastic lids but I am guessing that there are quite a few.
Therefore, I want to pass along something I learned by painful experience.
As you know, the plastic lids wear out eventually and you can buy
replacement lids. One did and I bought a replacement, put it on the
tank and put the tank with the others.
Perhaps two or three weeks later I processed a roll of film and
there were strange light streaks on it with increasing intensity
near one end of the roll.
I had never seen anything like this before so I check a lot of
things like the cameras, the developer, the darkroom for light leaks
etc. etc. This went on and one for a week or so. Everything checked
out OK but I was still getting fogging.
Finally, I held the plastic tank lid up to the light to check for
unseen tiny cracks and the problem was solved. There were no cracks
but the black plastic was not opaque. Something went wrong during
the maufacturing and the pigment in the plastic was absent in places.
In ordinary reflected light the lid looked OK. This could only be
seen when it was held up to a 100 watt light bulb. The pigment was
more absent near the center of the lid which explained why the fogging
was worse near one end of the roll.
Since I had bought several lids at the time I check these brand new ones out
and found another defective one. Since then I have checked
all my plastic lids and all the ones at the College and have found
some more defective lids.
Moral: Before you flip your lid, hold it up to a 100 watt light
bulb and check it out.
I would be interested in knowing if anyone else has found defective
film tank lids.
Bob Schramm
Check out my web page at:
http://www.geocities.com/schrammr1/schramm_studioa.htm
also look at:
http://www.wlsc.wvnet.edu/www/pubrel/photo.html
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