From: edwin m (email suppressed)
Date: Tue Oct 19 2010 - 05:03:28 PDT
i've never used it, but i've seen before that companies (including jobo & ilford i think) sell anti-oxidising sprays that you can fire into the top of a container before sealing, significantly improving shelf life. they work for everything except bleach, which you should always mix fresh.
most kits have detailed instructions for chemical efficiency somewhere in the back - there are various ways of combining/splitting baths, etc., that mean the process will have more steps, but be more efficient. you get a hi-five from Mother Nature too, as long as she doesn't remember you're the guy who's been pouring all those chemicals into the water system for all these years
edwin
Date: Mon, 18 Oct 2010 20:45:18 -0700
From: email suppressed
To: email suppressed
Subject: Re: [Frameworks] B&W chemicals - how many uses?
Ekrem,
Too many variables to address easily, but the long and short of it is that air in a container will cause the developer to oxidize quickly and become ineffective. Some people use inert glass marbles to fill in the extra space, and preserve chemistry. Also, when you dilute a developer it tends to undermine its shelf-life.
One enthusiast I know keeps his chemistry in plastic gasoline containers and has a nitrogen tank with a special nozzle attached. He can then clear out as much of the oxygen as possible and seal the container. I suppose you could by an argon gas container for preserving wine and do the same thing.
I've often been able to get good results with D-76 1:1 for about 1000 feet, over 2 months. Likewise with Dektol 1:4. I don't use D-19 often, so I tend to
mix up a 1 liter batch, then dilute 1:3. I'll process a few hundred feet and call it a day.
One of my favorite books for a basic introduction is the Darkroom Cookbook. Not only does it explain what each of the steps in development do, but it has a glossary of many of the most commonly used chemical compounds, and some recipes for standard B&W developers.
Good Luck!
-Jason Halprin
From: Ekrem Serdar <email suppressed>
To: Experimental Film Discussion List <email suppressed>
Sent: Mon, October 18, 2010 5:32:29 PM
Subject: Re: [Frameworks] B&W chemicals - how many uses?
Well, according to what Gary Popovich writes in Recipes for Disaster, you're using it relatively "correctly" (he mentions two batches of developer for every four hundred feet or so).
I've used 400ft of 16mm with a batch of D19, mixed in a gallon and then further diluted with another three gallons of water and it seemed a little milky (tri-x) but fine.
I'd actually be curious what the "limits" of a variety of handprocessing mixtures are, for how long they keep when mixed, how many feet they'd be "good" for and perhaps ways to replenish them. I've heard some chemicals lose their efficiency after about a week of just sitting around... I'd love to hear some frameworkers go off on this one!
On Mon, Oct 18, 2010 at 5:16 PM, John Woods <email suppressed> wrote:
So the common Kodak packages of D-76, D-19, Hypoclear, etc. usually make 3.8
liters or 1 gallon. I was wondering how much film you can process with this
amount with consistent results. I usually process batches of 3-4 super 8
cartridges at a time and then dispose of the chemicals. I'd like some advice on
whether I could be more efficient with the chemicals or if I'm depleting the
chemicals with the amount of film I use. Thank you!
John Woods
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-ekrem serdar
austin, tx
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