Archived posting to the Leica Users Group, 2000/08/16

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Subject: Re: [Leica] BW developments
From: Richard Comen <>
Date: Wed, 16 Aug 2000 10:07:27 -0700
References: <> <000001c0062a$43a42d80$d73140c3@pbncomputer>

Chris, if one is clever, they know better than to be rich and famous. As to
the Tech Pan at ASA 100, the following is the formula for the brew two of
us spent a few years working on. It is very inexpensive, simple to make and
it keeps well in individual 8 oz bottles. I mix 3 liters of it and place it
into 8 oz. amber glass tightly stoppered bottles obtained from my
pharmacist.  The following is the brew:

Directions for Pota-HC110 developer for processing Tech Pan at ASA 100:

In 300 ml hot water mix 1 tablespoon Sodium Sulfite and 1/8 teaspoon
Phenidone . I use the set of plastic measuring spoons that come in a set
for kitchen use. In the UK spoon measurements may be different. In weight
it is 22.8 Gms Sodium Sulfite and .35 Gms Phenidone. ( If it had not been
for the intransigence of King George [  1776 ] the UK and the US  would
probably  be using the same measurements today). To the above add 2 ml.
HC110 syrup ( measure  with a child's medicine syringe found at any
pharmacy ). 

pharmacy ). 

 The measuring spoons mentioned above are just fine, extreme accuracy is
not necessary. Filter through coffee filter  that is placed in a funnel.
Cool to 68 degrees F. Use stainless nikkor tank for one roll only. Discard
developer after one roll, ( Phenidone developer oxidizes rapidly and should
be discarded after one roll). I place tank  in a tray of water that is 68
degrees to keep temp constant. Develop for 6 minutes. After filling tank,
rap tank to dislodge air bubbles, then give one gentle inversion over and
back. Place tank in water bath of 68 degrees. Agitation:  Do not agitate
until beginning of third minute and at that time one gentle inversion over
and back. Repeat at top of each remaining minute.  At end of 6 min., drain,
use short stop, and follow with rapid fix for aprox 2 min. Wash as usual,
rinse in distilled  water for final rinse, then instead of foto flow, pour
in rubbing alcohol ( I prefer it to foto flow.  It is often on special at
pharmacies for 39 cents a bottle ). Let sit in alcohol for a minute or so,
discard alcohol and hang film to dry ( no squeegee or sponges as that is a
terrible thing  to do to wet film). Hang in dust free place.  ( If  I sound
dogmatic at times, it is because I am dogmatic at times ). Because of
variations of meters, camera shutters, thermometers, and other variables,
you might want to adjust your time of development slightly. 

Since concocting the above brew formula, I have found that it simplifies
life to mix 3 liters of the above brew ( use 10 x the brew formula ),
filter as above and pour into 8 Oz. Brown glass bottles obtained from a
pharmacy. Fill each bottle so that there is no air and screw on top
tightly. I have found that using my last bottle 6 months after mixing gives
the same results as with the first bottle used right after mixing. All I do
is place a bottle into 68 degree water bath and when brew reaches the bath
temp, I pour it into the tank. 

ASA 200 can be achieved  by increasing the developing temperature to 70
degrees F. and following the rest of the above procedure. There will be a
loss in shadow detail however.

The above gives me the best negatives  I have ever made and they print
beautifully with the split filtration method and they are beautiful on the
new Ilford cooltone MG pearl paper.


Scroll Photos by RichardC at bottom of page, See album titled Tech Pan at
ASA 100.
Please allow for my inexpensive scanner and for JPEG quality.

Chris, I will be in Agde, France  for the month of October so can show you
some prints in person if you care to drop in for some wine.         Richard

At 11:04 AM 8/16/00 +0100, you wrote:
> Technical Pan.
>>I find it unsurpassed for any subject matter we choose. The only problem
>>with it was the ASA 25 rating and the use of technidol developer. I have
>>spent the last six years overcoming the slow ASA rating problem and now
>>have evolved a method of using the film at an honest ASA 100 with full
>>tonal range, especially with the use of split printing and the new Ilford
>>cooltone paper, but it works almost as well with most any VC paper.
>Well Richard, as they say in Germany, let the cat out of the sack! What's
>your method? How do you get no grain without losing acutance and with full
>shadow detail at e.i. 100. Is it low cost too? Let us know, because
>otherwise we'll have to ask ourselves: if you're so clever why aren't you
>rich and famous?
>Christer Almqvist
>D-20255 Hamburg, Germany and/or
>F-50590 Regnéville-sur-Mer, France

In reply to: Message from Richard Comen <> (Re: [Leica] BW developments)
Message from "Erwin Puts" <> ([Leica] BW developments)