The Beutler formula is a semi-compensating formula, meaning the compensating action's affect is at the higher densities. The highlights. Pyro, on the other hand is a fully compensating developer, meaning it also alters densities below Zone 4, affecting the shadow detail. Pyro is also a 'tanning' developer, the tanning being part of the oxidizing arrangement, turns the negative to a chocolate brown, instead of the normal charcoal black of most negatives. It is the Preservative (sodium sulfite) that controls the amount of tanning action. The accelerator controls the energy of the developer and the ultimate acutance.
When the sodium sulfite is reduced, the tanning of the negative increases, however, there also occurs a bit of what might be said to be 'textural fogging' as it is the sodium sulfite that keeps the oxygen from being absorbed by the pyro, hence tanning/fogging. Too much sodium sulfite and it retards the pyro tanning that is desirable. One of the original accelerators used with pyrocatechen was the standard sodium carbonate. Actually a very good formula. However, once I switched to sodium hydroxide I never went back. Sodium hydroxide is the most volatile of all the photo chemicals. A quarter teaspoon of that plopped in a 1000ml beaker of cold water will make it boil. Should you make the mistake of pouring water over the same amount in a beaker, very bad things will happen, including burns to whatever part of your body the resulting chemical explosion reaches. Be very careful with sodium hydroxide.
The primary reason I altered the formula was due to this chemical's volatility. I mix a 10% solution of sodium hydroxide, then add the ml needed; 1ml = 1g equivalents in a give formula. Much easier to measure out 4ml of hydroxide to add to a formula than attempting to add the dry powder to the liquid. Being I learned most of my photo-chemistry from old books I could find on the subject, my education derives from practices of much earlier times, such as the use of pyro/OH developing Kodak's super XX 250 film. So said the 'leading' photo book on portraiture, circa 1930's & 1940's. The reason given was the tonal qualities for skin tones, and it's unrivaled acutance. That is something I can say without question remains true today. Two things that make a pyro/OH negative stand out, is the chocolate color and the bah relief feel of the emulsion side. You can literally feel the edges of the emulsion when you run your finger over the emulsion side. It shows up quite nicely in the image as well.
As I pointed out above, the compensation action affects both the shadows as well as the highlights. A choice has to be made when using pyro, concerning shadow detail. Normally, it is desirable to under-rate the film 3/4 to 1 full stop when using a compensating developer. However, just know that doing so when using pyro, increases shadow detail by increasing densities to the lower tonal densities. For some, this would be a wonderful thing. For those that want the W. Eugene Smith look to their images, with lots of deep blacks from Zone 3 and below, you can simply rate your film as indicated and add a small amount of developing time as needed to control highlights. Easy enough to do by proper placement of values before clicking the shutter.
It should also be noted that there is another way around mixing a full 1000ml bottle of pyro, beyond the method I employ, which is to simple make a two stock solution then mix before use. I just found the mix and use method to my liking. I will leave both formulas;
Windish Pyro; Two stock solutions Measuring spoon method
Solution A;
Water @115 deg 350ml
Sodium Sulfite (anhydrous) 20g 1/2 Tbl + 1 1/8 Tsp
Pyrocatechin 10g 2 1/2 Tsp
Cold water to make 500ml
Solution B;
Potassium Carbonate (anhydrous) 60g 3 Tbl + 1 Tsp
cold water to make 500ml
Dilution: Equal Parts A:B
Developing Time; 7 minutes
Single Use Formula; "Tanning Formula" (use of hydroxide makes it a tanning formula)
Solution;
To 1 oz water @110 Add 3 ml (10% solution) sodium sulfite
then stir in 1 g (1/4 Tsp) Pyrocatechin
Tank or Tray development;
[24 oz ~ 735ml] 15 ml solution
add to 735 ml water
then add 4.5 ml (10% solution) sodium hydroxide
[16 oz ~ 490ml] 10 ml solution
add to 490 ml water
then add 3 ml (10% solution) sodium hydroxide
Developing; ISO 125 ~ 10 minutes; ISO 320/400 ~ 13 minutes
Constant agitation first minute; with 15 seconds agitation each minute thereafter, for best results.
The differences between these two formulas can be seen mostly between the accelerators, with the first formula using carbonate and the second using hydroxide, making it a 'tanning' developer. It is the oxidation brought on by the hydroxide that facilitates the tanning. Although a pyro negative is a chocolate color and appears to be a bit 'thin' in the densities, the densities are nevertheless there.
This is the developer I used almost exclusively for my artwork, consisting mostly of scenics at the time. I have yet to have anything yet to develop with pyro so will have to post an old image of a salted silver print, made from a pyro/OH developed negative. The negatives in this Oregon portfolio are in the range of Log 1.2 density range; developed in the Windish pyro/OH formula for 20 minutes.
Un-toned Salted Silver Print
"Jerome House" ~ 5x7
Jerome, Arizona
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