[Leica] Ups and downs of stop baths?

[henningw at archiphoto.com (Henning Wulff)]

At 2:55 PM -0800 11/22/05, Adam Bridge wrote:
>So I've gotten this general impression that a substantial number of
>folks aren't fans of stop baths for black and white negative film and
>just slosh around water in its place which.
>
>So what's the thinking here? The stop bath gets in the way of fixing
>later? Has some bad effect on film grain? I would assume that it would
>be a good thing to quickly stop the development process.
>
>Now when using very dilute devopers, like XTOL 1:3 where it's
>essentially completely expired at the end of development, I can see
>that just washing the film for 30 seconds with water might not be a
>bad thing. But what about 1:1? Or some other developers?

The main problem is that pinholes can develop. If 
you do use any 'stop bath', dilute it a lot.

I'm not in a real hurry to get the negs done, so 
try to have my development times in the 10min. 
plus range so that pouring times/effects don't 
interfere. When you do that, and do it 
consistently, the additional development that 
occurs during the water bath is easily dealt with 
as you test your procedure.

Then again, if you are a volume user and develop 
6 or more rolls at a time in a tank, you 
shouldn't use very short development times as 
then you will get streaking due to some portions 
of the film getting a lot more developer time as 
a percentage than the rest.

For evenness and general quality I use a presoak, 
and then develop HP5+ in Xtol 1:3 with decreasing 
agitation, letting it stand for 5 minutes at the 
end for a total time in the developer of 17min. 
at 21?C. All this with 7 rolls of 36 in a SS 
Nikor tank intended for 8, with the 1:3 developer 
going to the top. Then a water bath, etc. Delta 
100 gets treated similarly, but for less time. I 
get an effective speed of 200 for the Delta 100, 
and 64 to 800 for the HP5+. Tri-X gets me 400 
using a similar technique. Xtol seems fairly 
sensitive to water quality, and this will also 
affect your times. I use local tap water, but 
both hot and cold are filter with a particle 
filter, and the mixed water is again filtered 
through charcoal. I had this setup long before 
Xtol came out, and it works fine and gives me 
peace of mind.

The developer is essentially exhausted as you 
indicated, and only the shadow areas get some 
development in the last 5 minutes. That's why I 
get an effective speed increase.

All this said, I haven't used stop bath since the 
60's, when I did have some problems with pinholes 
and stopped using it. That was in a different 
place, with different water and D-76. That water 
wasn't filtered, or certainly not as well, and 
particulates in the water in combination with 
stop bath can cause further problems.

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    *            Henning J. Wulff
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