From: Clay (wcharmon@wt.net)
Date: 12/04/02-06:10:11 AM Z
Scott:
Sorry, my first reply didn't have a reply attached to it! Stupid
computer user problem, I suspect.
First, you don't need to stick the film back into the used developer.
That will only give you general, non-useful stain. Next, I would use a
1:2:100 or a 2:2:100 dilution, which will significantly shorten your
developing time. and keep your fogging to a minimum. With 1:2:100, it
is rare that I need a developing time in excess of 11-12 minutes for
even a very low SBR subject, such as a foggy (real, natural fog, not
film fog) photo. I have found that pyrocat gives me very close to the
advertised film speed on most films. Down-rating your film to 100 will
guarantee you dense, almost unprintable negs. The problem will be that
your shadows will be vastly overexposed, and your highlight density
will be limited my the tanning action of the developer. In other words,
the worst of both worlds for alt-process negs: dense and flat. I find
that pyrocat as very little base+fog, especially when compared a
developer such as PMK.
I recommend you go through the Phil Davis BTZS test procedure. It is
much more straightforward than what you described. Then use one of your
pyrocat developed test wedges to do a print test for your chosen
printing process.
Good luck,
Clay
On Wednesday, December 4, 2002, at 06:05 AM, Clay wrote:
>
> On Tuesday, December 3, 2002, at 11:36 PM, Scott Wainer wrote:
>
>> Hello all -
>>
>> I'm hoping someone out there can help with my problem.
>>
>> Problem:
>> After reading "The Book of Pyro" and visiting www.unblinkingeye.com,
>> I recently switched from Ilford ID-11 film developer to Pyrocat-HD
>> with the hopes of getting negatives that have better tonal
>> seperation, are sharper, and have less grain. I am currently
>> performing film speed tests with Ilford Delta 400 (4x5) which I will
>> use to create enlarged negs (via Liam's reversal process) for contact
>> printing. I believe that I am getting excessive general fog;
>> causing extreamly slow film speed results.
>>
>> Processing:
>> I chose 15 minutes as a starting time and tray developed (with
>> gloves) at a dilution of 1:1:100 (see below for formula); agitating
>> for 15 sec. every minute. I used a water stop (2 min.) and fixed (2
>> min.) in TF-3 Alkaline Fixer without Sod. Sulfite. I then returned
>> the film to the developer for 2 min. without a rinse, washed for 20
>> min., and dried.
>>
>> Having a B&W densitometer, I could not get an accurate density
>> reading from the stained film. Using the process for estimating
>> negative density without a densitometer found in the Ansel Adams
>> Guide : Basic Techniques of Photography, I did the following:
>>
>> 1. Print a very light tone using a unexposed, undeveloped piece of
>> film cleared in fixer. I used the densitometer to measure the density
>> of the print which I recorded along with the time (A) to make that
>> tone.
>>
>> 2. I then printed an unexposed piece of film developed in Pyrocat-HD
>> to the same tone as in step 1, using the densitometer to ensure the
>> density of the print matched that the original. Again, I recorded the
>> time (B) to make that tone.
>>
>> 3. Next, I printed a piece of film exposed for Zone I and developed
>> in Pyrocat-HD to the same tone as in step 1, using the densitometer
>> to ensure the density of the print matched that the original. Again,
>> I recorded the time (C) to make that tone.
>>
>> 4. Finally I divided the times B & C by the time A to come up with
>> the ratio for steps 2 & 3. I then compared the ratios for steps 2 &
>> 3 against the Exposure-Density chart.
>>
>> What I came up with was that the density for base+fog (neg in step 2)
>> was approximately 0.22 and the density for exposure (step 3) was
>> approximately 0.24. Assuming I need a density of 0.10 above base+fog
>> for zone I, I would have to rate my film at EI 100 for a 400 speed
>> film (a loss of 2 stops).
>>
>> Question:
>> The newer version of Pyrocat-HD uses a 100% soln. of Pot. Carbonate -
>> the older version used a 10% soln. of Sod Carbonate. Per Anchell's
>> The Darkroom Cookbook, Pot. Carbonate is stronger than Sod. Carbonate
>> - needing 0.90x the weight for subsitution. According to The Book of
>> Pyro, pyro combined with a strong alkali (higher ph)increases base
>> fog. Should I revert to the older formula? I also read that Ed
>> Buffaloe (unblinkingeye) used a 10% soln. of Sod. Hydroxide (even
>> higher ph). Does a 10% soln. of Sod. Hydroxide have a lower ph that a
>> 100% soln. of Pot. Carbonate?
>>
>> Plea:
>> Pleasssssssse, somebody set me straight. I will have to go back to
>> ID-11 (sigh) if I can't straighten this out. I want it all - better
>> tonal seperation, sharpness, and less grain at somewhere close to the
>> manufacturer's ISO/ASA.
>>
>> Thanks in advance from a newbie,
>> Scott Wainer
>>
>>
>> The Pyrocat-HD formula I use is:
>>
>> Stock Soln. A
>> Sod. Bisulfite 1 gm
>> Catechol 5 gm
>> Phenidone .2 gm
>> Pot. Bromide .2 gm
>> Distilled Water to make 100 ml
>>
>> Stock Soln. B
>> Pot. Carbonate 100 gm
>> Distilled Water to make 100ml
>>
>> Diluted 1:1:100 with distilled water
>>
>
This archive was generated by hypermail 2.1.5 : 01/31/03-09:31:25 AM Z CST