Archived posting to the Leica Users Group, 1999/11/26

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Subject: [Leica] Agitation problem
From: Mike Johnston <michaeljohnston@ameritech.net>
Date: Fri, 26 Nov 1999 17:18:06 +0000

I have also put up a page about a negative problem that I can't seem to
shake. Is it over or under agitation, or something more subtle? A reward
(!)
is offered to anyone who finally helps me nail this. Details at:

    http://www.cinematic.freeserve.co.uk/Pages/filmdev.html


Johnny,
That's bromide drag (streaking) from the sprocket holes, caused by
underagitation. I'm betting you fill your developing tank all the way to
the top. This is what's causing the problem. Stop filling the tank all
the way--leave an airspace, the more generous the better. The problem
will go away.

I'd also recommend that you dilute your developer further and use a
longer developing time--longer than 5 minutes at least--but that's up to
you. The airspace should solve the problem.

George Post did a very nice and incredibly thorough article called
"Shake It Up!" published in the old _Darkroom Photography_ in the '80s.
That's the best article on agitation I've ever read, just in case you
want to read up on the issue further.

- --Mike