SCHRAMMR@WLSVAX.WVNET.EDU
Mon, 22 Feb 1999 21:03:45 -0500 (EST)
Hello All,
I want to tell the list about a problem I had and just solved this evening
after about six months of fooling around. Since this could happen to almost
any of you on the list, I think you will be interested.
As staff photographer at West Liberty State College I use a lot of rolls of
film. For B & W, I use T-Max 400 in both 35 mm and 120. About 6 months ago
I started getting what looked to me like fogging.
At first I thought the camera I was useing had a light leak so I tried two
other cameras. No matter what camera I used, I still got fogging. Since
these same cameras are used for color film as well, and there was no
evidence of fogging of the color film, I eliminated the camera as the problem.
Since I process my own B & W film, I decided to double check my processing.
I mixed up new chemicals, checked everything very carefully. I began to notice
that sometimes I got fogging and sometimes I did not even though the chemicals
were the same. This led me to the film itself.
I buy film from a wholesale source that has the State contract. I will
typically buy 40 to 60 rolls at a time. I began recording batch numbers and
trying to correlate that with the fogging. There seems to be no discernable
pattern.
Next I bought some film from B & H Photo in NYC where I buy all my personal
film and chemicals. Same problem i.e. random fogging of 35 mm and 120 film.
I began testing different rolls of film from different batches by loading
unexposed film into the developing tank and processing it. At that point
, since I was using unexposed film, I could easily see the fog pattern. The
pattern was the same on all rolls of film that were fogged in both 35 mm and
120.
I have maybe eight stainless steel tanks in my darkroom of various sizes.
The kind with metal reels and a plastic top. Knowing that the plastic tops
sometimes crack when they get old, I had checked them all very carefully for
cracks. Having eliminated everything else, I held all the lids up to the
at 75 watt light above the developing area.
Sure enough, one of the lids, though not cracked, was made of a plastic that
was defective so that a small amount of light could filter through the black
lid around the edge. Aparently whatever was put in the plastic to make it
opaque didn't work. The lid looks normal otherwise. Only when you hold it
up to a strong light can you see this.
Problem solved.
I therefore strongly suggest to you that you might want to check all your
plastic lids the next time you are in the darkroom
Well, the Master said,
"When you have eliminated the impossible, whatever remains,
however improbable must be the truth."
Bob Schramm
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