Question for the APUG chemists

[Chuck_P]

I have several prints developed in hc-110 (A) as seen stated on the Covington Innovations site because I was out of dektol and decided to give it a try. I was quite pleased with the final outcome of the prints, they were somewhat softer and the blacks seemed to develop differently, i.e., softer as well but totally acceptable. What is the action taking place to cause this difference between dektol and hc-110?

What other prepared print developers will provide this somewhat softer development of the print? I have only used dektol but would like to try others.

Chuck

 

[john_s]

Basically film developers are more gentle than paper developers. They usually have lower pH, making the developing agents slower, and are often, though not always, more dilute. Paper developers also are designed to produce no fog, but some is usually tolerated in a film developer.

Rodinal 1+25 is reputed to be a very nice warm tone paper developer, but I suppose with its current scarcity this would be viewed as wasteful, if not sacrilege.

From a rec.photo.darkroom post by Richard Knoppow,
"Rodinal makes a good, if expensive, paper developer. Dilution is as for film, 1:25 to 1:50, the very old Agfa ads suggested 1:30. It might need some added bromide, a couple of grams per liter of working solution."

 

[Jordan]

I think John has it -- film developers are inherently "softer working". I would also add that HC-110 has anti-fog agent(s) in it, which may make it "more suitable" as a paper developer.

 

[photomc]

I have used Rodinal as a paper developer and it gives good results. And I think our own Donald Miller has modified Pyrocat-HD to use as a paper developer - the article might in the articles section here on APUG, but I am pretty sure it can be found on unblinkingeye.com

 

[glennfromwy]

I've used Dektol to develop film but not the other way around. Interesting. Kodak Selectol Soft is a soft working developer for paper.

 

[Donald Qualls]

I developed paper in HC-110 (dilution A, as I recall) something like 30 years ago. Worked fine then, though one paper I had (Velox, as I recall -- a huge bax in contact printing size that I rescued from a trash can) came up with extremely cold, distinctly blue tones, which would turn very warm, almost sepia, if I turned on a white light while the paper was in the stop bath.

Say, maybe I should try it again to see if it'll beat the fog in this 40+ year old packet of Velox I have now?

 

[Tom Hoskinson]

I have used Rodinal as a paper developer and it gives good results. And I think our own Donald Miller has modified Pyrocat-HD to use as a paper developer - the article might in the articles section here on APUG, but I am pretty sure it can be found on unblinkingeye.com

fellow APUGers Donald Miller and Jorge Gasteozoro (spelling?) came up with PPPD.

PPPD is Phenidone Pyrocatechol Pyrogallol Paper Developer.

AFAIK PPPD is not a modification of Pyrocat

(there was a url link here which no longer exists)

Donald Miller's PPPD (Pyrogallol, Pyrocatechol, Phenidone Developer) paper developing formulation.

43 gm Sodium Sulfite
.3 gm Phenidone
10 gm Pyrocatechol
5 gm Pyrogallol
50 gm Sodium Carbonate
3.5 gm Potassium Bromide
Water to make 1 liter

Dilute 1-1 to make 2 liter of use solution

The phenidone should be dissolved in alcohol just as in the Pyrocat formula
As in all cases where exposure to Pyrogallol is involved, eye protection, nitrile gloves, and respirator should be worn. (Just as in any pyro formulation).

Alex Hawley has reported good results with his modified version of PPPD. Alex removed the PyroGallol from the formula and replaced it with Pyrocactechol. He also added some Citric acid (how much citric acid?? PM him)