On May 5, 7:56=A0am, jch <j...@[EMAIL PROTECTED]
> wrote:
> _____
> Hello All,
>
> I have been reading about divided developers for film. =A0Never tried
it;
> looks promising though! =A0Do any of you in this group have any
experience=
> with this approach? =A0The reason for my interest is the fact that i
live
> in the country and that my house disposes of waste water via a septic
> tank system. =A0Hence, i want to minimise the amounts of photographic
> chemicals entering the tank in case they kill the microbes.
>
> Below is a divided developer formula; a variant on D-76 where BATH A and
> B can be kept for a long time:
> =A0 =A0A BATH
> =A0 =A0 =A0Water at 125F =A0 =A0 =A0 3 cups
> =A0 =A0 =A0Metol =A0 =A0 =A0 =A0 =A0 =A0 =A0 1/2 tsp
> =A0 =A0 =A0Sodium sulfite =A0 =A0 =A02 TBL
> =A0 =A0 =A0Hydroquinone =A0 =A0 =A0 =A02 tsp
> =A0 =A0 =A0Potassium bromide =A0 1/8 tsp
> =A0 =A0 =A0Cold water to make =A01 quart
>
> =A0 =A0B BATH
> =A0 =A0 =A0Water at 80-100F =A0 =A03 cups
> =A0 =A0 =A0Sodium sulfite =A0 =A0 =A02 TBL
> =A0 =A0 =A0Borax =A0 =A0 =A0 =A0 =A0 =A0 =A0 2 TBL
> =A0 =A0 =A0Cold water to make =A01 quart
>
> Process 2-4 minutes in A BATH, and the same time in B BATH, both at 68F.
> =A0 Agitate for 15 sec initially, and for about 5 seconds every half
> minute. =A0Stop bath is not recommended after B BATH, a quick 1 min
rinse
> in water is enough. =A0Fix the film in the usual manner.
>
> A BATH will last indefinitely, and B BATH can be used for 20-30 rolls of
> film before any change in contrast or density should be noticed.
>
> There is also a phenidone version of this formula to obtain increased
> film speed.
>
> --
> Regards / JCH
Not sure what to make of this, but at least A BATH will deteriorate
with use and with time. The usual interpretation of "indefinitely" in
"A BATH will last indefinitely" is misleading. The lifetime may be a
little uncertain, but it will steadily deteriorate.
As B BATH becomes contaminated with A BATH it will at least look
ugly.
Metol and Hydroquinone decompose in air. They are the more
troublesome parts of your mix (although I don't necessarily recommend
drinking a lot of borax). Unless you process a whole lot of film, you
may be just as well served by letting the used developer sit in a tray
for a few days before pouring it down the sink.
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