Jean-David Beyer wrote:
> jch wrote:
>> _____
>> Hello All,
>>
>> I have been reading about divided developers for film. Never tried it;
>> looks promising though! Do any of you in this group have any
experience
>> with this approach? The 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. Hence, 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:
>> A BATH
>> Water at 125F 3 cups
>> Metol 1/2 tsp
>> Sodium sulfite 2 TBL
>> Hydroquinone 2 tsp
>> Potassium bromide 1/8 tsp
>> Cold water to make 1 quart
>>
>> B BATH
>> Water at 80-100F 3 cups
>> Sodium sulfite 2 TBL
>> Borax 2 TBL
>> Cold water to make 1 quart
>>
>> Process 2-4 minutes in A BATH, and the same time in B BATH, both at
68F.
>> Agitate for 15 sec initially, and for about 5 seconds every half
>> minute. Stop bath is not recommended after B BATH, a quick 1 min rinse
>> in water is enough. Fix 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.
>>
> I used several divided developers in the past for 4147 Plus-X and 4164
> Tri-X. I used D-23 or D-25 for Bath 1 and a solution of 2% Sodium
MetaBorate
> and 2% Sodium Sulfite for Bath 2. I used up to 7 minutes in bath 1 and 3
> minutes in bath 2.
>
> The good part was the measured film speed went up one stop.
>
> The bad part is that it worked the opposite of what people said. They
said
> it would lower the highlight contrast while maintaining the contrast
> elsewhere. What I got was that it lowered the shadow contrast (even
though
> it increased the film speed). The only way to control the highlight
contrast
> was to reduce the time in bath 1, and that lowered the contrast
everywhere.
>
> When I switched films to the TMax series, it was even worse because all
the
> sulfite made the sharpness very mushy. So I gave it up entirely.
>
_____
J-D,
An off-topic question: i noticed that you run Linux. What distribution
are you using these days? I started with Red Hat Linux about 1998, but
now i run OpenBSD for the past couple of years.
/ John
--
|
