a different logic to stand-dev

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andynguyen
Posts: 37
Joined: Wed Feb 24, 2016 8:45 pm

a different logic to stand-dev

Post by andynguyen »

well, we all know stand-dev & the way people most usually do it is agitation for 30s, then stand it for whatever amount of time they desire. The reasoning is that if there is no agitation then the chemical exchange happens mostly via diffusion & a little bit of convection due to density gradient.
This results in "pulled" highlight while giving shadows enough time to show up.

I've read a few claims that because stand dev allows shadows to come up almost fully, it's the method that yields highest effective ISO. but this also results in under-dev highlight which may or may not be to your expectation.

Now enters my proposed "mod": agitate for 30s, stand for 30 mins, then agitate every 5s for the next 2 minutes then stop bath.

The reasoning is this: since we start with very high dilution & a very diluted dev, by the end of 30 minutes, the amount of dev left is very minute and the shadows should already dev-ed fully. therefore the next 2 minutes of "normal" agitation will allow the highlight to further develop, perhaps by just a little to make a difference & not enough to blow them off.

I've not tried it. This is just a hypothesis & I'm throwing it here for comments before I have time to run some test. I'm not a fan of stand-dev, but I'm in-charge of bw dev for a lab so I've seen a lot of queries about stand-dev & it just occurred to me there might be this way to harness more from it.

What do you think?
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sanchell
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Joined: Mon Feb 13, 2012 8:47 am
Location: Oregon
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Re: a different logic to stand-dev

Post by sanchell »

Interesting hypotheses, Andy. I'll be interested in hearing the results of your testing.
Do it in the Dark,



Steve Anchell
andynguyen
Posts: 37
Joined: Wed Feb 24, 2016 8:45 pm

Re: a different logic to stand-dev

Post by andynguyen »

ok, i'll run a test next week. 1 roll of film cut in half & rodinal should suffice. I'll measure the neg density with my Kodak color densitometer. Hopefully it will yield some sort of difference
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