Divided Developer for paper

I'll post these formulas both on this newsgroup and on APUG. Several
people have inquired about the divided developer printing method I use.

First, some general remarks: Divided developing is not a new idea. I
ran across it first about 25 years ago in an old Dignan booklet of
formulas, and have used it ever since. The concept is simple: by
separating the activating agent from the developing agents into two
separate baths, several things are accomplished:

1. Time/temperature considerations virtually disappear. Since no image
appears in the developing agent bath (Bath A), any temperature will do.
I've tested at temps ranging from 50F to 100F with no discernible
difference. Your ambient darkroom temperature will do just fine. All
that happens in Bath A is that the latent image created by exposure
under the enlarger absorbs the amount of developer it will need to fully
convert the silver ions. As a result, Bath A never becomes exhausted;
it only get used up physically in volume as each sheet of paper absorbs
a tiny amount. It can be re-used indefinitely. Generally, about 20-30
sec. in Bath A is sufficient for the absorption to take place.

2. Since no actual image appears in Bath A, and in Bath B, only the
absorbed developer is activated, one cannot over- or under-develop as
long as sufficient time is given for absorption of the solution. Any
density changes will have to occur under the enlarger, thus making you
become a better printer.

3. Contrast is automatically controlled. You cannot increase or
decrease contrast by leaving it in the soup longer or pulling it out
sooner. You can leave it in Bath B all day and it will develop no
further than what the absorbed developer from Bath A permits. Again,
learn to control contrast under the enlarger. EXCEPTION: by using a
soft contrast developer formula for Bath A instead of the harder
formula, you can decrease contrast approx. 1 paper grade.

4. 2 liters of Bath B, which is just sodium carbonate (Arm & Hammer
Washing soda) will process approximately 35-40 8 X 10's before beginning
to become exhausted (weak blacks, muddy grays). Just discard and
replace, at a cost of mere pennies. While the image can't over-develop,
it can under-develop if you pull it too soon. At a normal ambient temp
of around 70 degrees, it usually takes about 45 seconds to fully
develop. The warmer your developer or room temperature, the shorter
time it will take. I've never had it take longer than 45 seconds, even
with a weakened solution. So the total time saving per print is
considerable.

5. Bath A will keep more or less indefinitely, because the preservative
is in it, but not the activator. Don't contaminate Bath A with Bath B
or you turn it into a weak single-solution developer and all bets are
off. In actual fact, I've kept it going for as long as 9 months without
noticing any degradation. Once I had to stop printing for nearly a
year, and the solution did go bad during that period. So figure on a
6-9 month shelf life before mixing fresh (again, at very low cost).

Here are the formulas:

_Normal-hard Bath A _ to make 2 liters
_Soft Bath A_

2 teaspoons Metol 2
Tablespoons Metol
3 Tablespoons Sodium Sulfite 3
Tablespoons Sodium Sulfite
2 teaspoons Hydroquinone 1/4
teaspoon Potassium Bromide OR
10 ml Benzotriazole (not both) 10 ml
Benzotriazole (not both)

_Bath B_

2 liters water
1/2 cup sodium carbonate

No water rinse or stop bath between Bath A and Bath B.

I've also tried E-72 which is a Phenidone, Vitamin C formula for Bath A,
but find that with the divided development technique, an extra boost is
needed, so I add a teaspoon or two of Hydroquinone to the Phenidone,
Vitamin C, and that does the trick.

Larry Kalajainen