[LargeFormat] A better way

[Pete Caluori]

From: Richard Knoppow <dickburk@ix.netcom.com>
Date: Wed, 07 Aug 2002 22:46:21 -0700

<snip>
Previous stuff snipped...
   The anti-halation backing on most B&W film is a dye in the anti-curl
gelatin coated on the back of the support. It is not removed but
decolorized by the developer. The fixer usually will decolorize it too, but
more slowly.
   Color films, and some B&W films have the anti-halation layer coated under
the emulsion next to the subbing. Again, its decolorized by the developer.
   Now, you are correct that the back coated anti-halation dye will remain
if the processing solutions can't get to it. Color film doesn't have this
problem.
   AFAIK, the only backing which are actually removed are the Remjet
backings used by Kodak on Kodachrome and many motion picture films. This is
designed to be blown off using a water spray at the entrance to the
processing machine.
----
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com


Greetings Richard,

They say you learn something every day...  WRT to the anti halation coating, 
if what you say is true and I don't have reason to doubt you, why does the 
water turn a dark color on a presoak?  Isn't that the antihalation coating 
disolving?  That's what I've always thought; please enlighten me.

BTW, I'm specifically referring to certain (non-chromogenic) B&W films.

Regards, Pete

_________________________________________________________________
Send and receive Hotmail on your mobile device: http://mobile.msn.com