Divided developer formula for Ilfochrome

As Claudio requested and I promised, here is a formula I've used
successfully over the years with Ciba/Ilfochromes. I began trying
divided developers with Cibachromes about 25 years ago when it dawned on
me that since Cibas were essentially B&W silver emulsions with azo dyes
incorporated, the same attractions of divided developers for B&W
printing (lack of time/temp considerations, print to print consistency,
automatic contrast control, easy alternative to masking) might work for
Cibas, which were notorious for being too contrasty.

After some experimentation, this is the formula that worked for me for
many years. CAVEAT: It may not work with current Ilfochrome emulsions;
I haven't done this for 5-6 years now, and I know that Ilfos now come in
different contrast emulsions. So experiment, but don't hold me to the
efficacy of this formula for current materials. Ilford has changed the
emulsions and chemistry from time to time. All I can tell you is that
while I was using it, I got Ciba/Ilfos that had the color vibrancy one
expects combined with contrast resembling C prints. The measurements
are all in kitchen teaspoon (t.) or tablespoon (T.) amounts. One other
caveat. The formula will work with metol instead of Phenidone equally
well, but there will be a significant color shift toward yellow that
will need to be compensated for in your filtration. As with most
Ilfochromes, once you've established your filtration for a given box of
paper, it usually stays pretty much the same for transparencies made
from the same film type.


Bath A: (2 liters water)

3 T. Sulfite
1 1/2 t. Vit. C
1/4 t. Phenidone (or 20 ml 1% Phenidone solution
1/8 t. Hydroquinone (or omit for even lower contrast)
10 ml Liquid Orthazite or 1/8 t. Benzotriazole
1/8 t. Sodium Thiosulfate
1/8 t. Potassium Ferricyanide (or 10ml of 10% solution)

Bath B:

3 T. Sodium Carbonate
2 t. Kodalk (metaborate)
1/2 t. Sodium Bisulfite
1/8 t. Sodium Thiosulfate (didn't know where to put the hypo, so split
it and put it in both A and B.)

Depending on how frequently you do Ilfos, you may want to mix in one
liter batches, in which case, half of everything above. In any case, I
always discard used Bath B after each session. A has very good keeping
properties.

Any temperature between 60-80 appears to work well. Colder really slows
it down, but doesn't affect results. Warmer works faster, but likewise
with no change to results.

With any divided developer process, the volume of Bath A gets used up
physically, but does not become exhausted. So Bath A can be used over
and over again until it's gone. Bath B can be used as a one-shot or, if
you're using a roller drum and only need 1 1/2-2 oz. of chemicals, you
can pour out half of the Bath B amount after use and the rest back into
your graduate to be topped up with a bit of fresh.

I usually filled two wide-mouthed graduates (grocery store pyrex
measuring cups work well), one with A and one with B, each with 500 ml
solution. If using a roller drum, pour A into the drum (amount is not
critical, so long as you use the minimum required for your drum),
agitate for (depending on temp.) 30 sec - one minute, dump back into
graduate. NO RINSE BETWEEN A and B.

Then pour in 2 oz. (or whatever your drum requires--again, not critical)
of B, agitate for at least a minute (if your room temp is around 70 or
above, a bit longer if it's colder). Pour out an ounce or so of B and
discard, and the rest back into the graduate. Add an ounce of fresh B
stock to replenish. A doesn't need replenishment; it just gets used up
gradually. With this method, I could usually get about 10-12 8X10's per
500 ml. of B during a session, but I never save used B solution.
Discard it after the session. Don't discard A--just pour it back into
the jug of stock.

Follow Ilford's procedures with the rest of the process, rinse, bleach, etc.

From experimentation, I eventually stopped using a drum and instead
tray-processed my Ilfochromes. You have to do the developer steps in
the dark, but as soon as you get the print into the bleach tray and
fully submerged for a few (10-15) seconds, you can turn the lights on.
Since temp is not a consideration for bleach either-- it bleaches to
completion but no further, so just make sure it's fully bleached
(normally 3-4 minutes) before putting it in the fixer-- your ambient
room temp will do nicely. You'll know when your tray of bleach is
getting exhausted; it won't do the job. If this happens, and it's quite
visible when bleaching is incomplete, add some fresh bleach to the tray
or throw out the old and put all new in. My experience has been that
all the chemicals will process more prints than Ilford says they will.

I may try some Ilfos again one of these days, and if I do, I'll report
any changes I've discovered.

Larry

"LR Kalajainen" wrote in message
...
big snip
Larry

Thanks Larry, I keep this post religiously and will give it a try.

Regards,
--
Claudio Bonavolta
http://www.bonavolta.ch