From: Richard Sullivan (richsul@earthlink.net)
Date: 06/07/02-08:55:06 AM Z
Manual,
This is a common problem with BPF and Expert tanks. It is the anti halation
coating not coming off.
I believe it was Carl Weese who first figured out this system.
When loading the film think of it as forming the letter "C" Make sure that
the opening of the "C" faces outwards from the center of the drum. This
allows the fluid to circulate behind the film better. Dunno why but it
seems to work most of the time.
You might also try loading the film into a drum with water in it. messy but
it works.
Or what I've done is to develop, fix in the drum. Opne the drum and fix
further in a tray -- this will remove any halation layer and then post
stain and wash in the tray.
For some reason the anti-halation layer on BPF is hard to get off.
--Dick Sullivan
At 02:22 AM 6/7/2002 +0100, you wrote:
>Hi all,
>
>
>Today I've printed Pt/PL with a 5x7 BPF 200 negative developed in Pyrocat
>HD.
>For the first time I noticed a strange phenomena. In the sky zone of the
>print a kind of blotches appeared that were not visible at all in the
>negative with transmitted light. Meanwhile I discovered that looking to
>the film from its back side making it reflecting a fluorescent light I
>could see funny colour areas identical to the ones we can see in the cars
>windshields when viewed through polaroid glasses.
>We can conclude that some of those irregular zones absorb more UV that
>others making those areas of different density to appear in the print.
>Could be a problem with the antihalation coating ?
>As I said before those areas are absolutely invisible through transmitted
>light.
>Those sheets were developed in a Expert tank. I tried to refix and washing
>them again but the problem remained.
>
>I've looked for other BPF sheets from other batches, developed in Rollo Pyro
>and I could notice the same phenomena.When the affected area is not sky
>nothing wrong appears to be wrong with the print.
>
>Perhaps some other BPF users could have something to say about this matter.
>
>Thanks
>
>
>Manuel Gomes Teixeira
>Punctum Studios Ltd
>Aveiro- Portugal
>EU
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