pyro developer, but which?

[onnect17]

Sergio,
I'm not familiar with the availability of chemicals in Bogota or how easy could be to place an order from outside the country. In any case, the SBR obtained from pyrocat-hd divided is amazing. Sandy helped me to find the right concentration and I developed some 35mm for testing. Check this sample, exposed for the shade and still you are able to see the white tower blasted by the sun in the background. Not adjustment was made, just invert.
Armando

I want to start developing with pyro. I am currently using 4x5 with FP4 and Fomapan 100. Will probaby open the repertoire to HP5 and that will be it at least for some time until I get a better feel for film again.

Sorry if this has been done to death here, but there is so much info on pyro that it is difficult to filter out. I am not a novice in the darkroom and have some experience mixing my own stuff, and I know how to handle chemistry and so on. But I have never used pyro and I closed my darkroom 8 years ago. Now i want to at least develop my film and scan afterwards. Maybe I'll start doing some contact printing which I guess is as far I can go in making prints at home with no darkroom. It has got to be airline friendly since I will fly it in the luggage. Which recipe do you think is best for my needs? What are your suggestions and advice on this topic? Thanks in advance.

[Jay DeFehr]

Jay,

I would be interested to understand your definition of a high contrast developer as it relates to the "nature" of pyrogallol and pyrocatechol. I have carried out numerous experiments using pyrocatechol and pyrogallol as sole reducers in formulas, and in combination with metol, phenidone and other secondary reducers. In almost every instance when pyrogallol and procatechol were used in the same amount (and pH adjusted to optimum for both reducers) I found that film would develop to about the same CI for equal time of development. From those experiments I conclude that pyrogallol and pyrocatechol are quite similar in the way they work and that either can be used to make both low contrast and high contrast developers, and in fact you can find examples of both in Anchell's and Troop's The Film Developing Cookbook.

Sandy

Hi Sandy,

A developing agent suitable for use in a high contrast (lithographic-type) developer should work in a very high pH environment without fogging, and exhibit a high sensitivity to bromide. Catechol does this, but pyro doesn't; hydroquinone does, but metol doesn't. Pyro and metol are too soft working to be used in a high contrast developer. All these agents can be used to make negatives of pictorial contrast. I hope this clarifies my comparisons of catechol to hydroquinone and metol to pyro.

Regarding grain, I don't take as hard a line as you do. While making Tri-x look like Acros might be a stretch, some developers can make TMY look like TMX, or Tri-X look like Plus-X, and that's significant.

Grain and sharpness don't differ enough among developers to be very meaningful for LF work, but the same cannot be said for smaller formats. It stands to reason the best developer for small formats should be more than good enough for larger ones. Film and format are far more important than developer.

[sanking]

Is there any inherent difference in sharpness and grain between the various pyro staining and tanning developers? In my opinion there is not, and I have carefully tested most of them.

Sandy

I should have qualified that statement by excluding old-time formulas such as ABC Pyro. This is an excellent formula for LF film but gives lower film speed and more pronounced grain than contemporary pyro formulas. At least the grain is fairly pronounced when using fresh sulfite. If the sulfite is old there will be more stain and this will reduce the appearance of grain considerably, but with much greater B+F or general stain, which will also reduce sharpness.

Sandy

[sanking]

Hi Sandy,

A developing agent suitable for use in a high contrast (lithographic-type) developer should work in a very high pH environment without fogging, and exhibit a high sensitivity to bromide. Catechol does this, but pyro doesn't; hydroquinone does, but metol doesn't. Pyro and metol are too soft working to be used in a high contrast developer. All these agents can be used to make negatives of pictorial contrast. I hope this clarifies my comparisons of catechol to hydroquinone and metol to pyro.

Regarding grain, I don't take as hard a line as you do. While making Tri-x look like Acros might be a stretch, some developers can make TMY look like TMX, or Tri-X look like Plus-X, and that's significant.

Grain and sharpness don't differ enough among developers to be very meaningful for LF work, but the same cannot be said for smaller formats. It stands to reason the best developer for small formats should be more than good enough for larger ones. Film and format are far more important than developer.

Jay,

OK, but from what you write I would conclude that pyrocatechol is simply a more versatile reducer than pyrogallol. It can be used in both low contrast and high contrast formulas,as well as in lith developers. But for pictorial use both pyrocatechol and pyrogallol can be used in both low contrast and high contrast formulas.

As regards grain and sharpness, most of my work these days is with medium format (and I print fairly large), so I have looked very carefully at the grain and sharpness characteristics of most of the contemporary pyro developers. There is almost no difference between any of them, and when there is an advantage to grain or sharpness, if you make a good comparison, you will find that a plus to grain means a slight negative for sharpness, and vice versa.

It would be nice if some independent body would do a comparison test of these developers, but in the absence of such people will come to their own conclusions and, as it were, vote with their money and time.

Sandy

[JMB]

Hypercat

A
Propylene Glycol 75ml
ascorbic acid 1g
catechol 10g
PG to 100ml

B
Sodium carbonate 20%


Dear Jay,

What is the function of the propylene glycol?

Thank you and Merry Christmas

[Jay DeFehr]

Sandy,

I would agree catechol is more versatile than pyro, but I don't think it's so simple. Pyro can do things catechol can't do as well, or in the same way. Pyro works at a lower pH and is less sensitive to the stain-killing effects of preservatives, so it doesn't oxidize as quickly, and lasts longer in a tray. Staining pyro developers can be formulated to produce finer grain than staining catechol developers. Pyro can be made as a single solution developer. Most importantly, pyro produces better gradation than catechol.

I too have tested most contemporary staining developers, and I disagree with your conclusion regarding grain and sharpness. If sharpness is the combined subjective effect of resolution and acutance, a finer grained print of higher resolution will appear as sharp as a lower resolution, grainier print of higher acutance. I think scanning favors resolution over acutance.

I don't care which developer anyone uses. Developer formulation is interesting for me, and I enjoy discussing the subject with others who share my interest. If something useful comes out of these discussions, all the better, but I don't crave arbitration or consensus. Developers are interesting, but not important.

[Jay DeFehr]

Hypercat

A
Propylene Glycol 75ml
ascorbic acid 1g
catechol 10g
PG to 100ml

B
Sodium carbonate 20%


Dear Jay,

What is the function of the propylene glycol?

Thank you and Merry Christmas

The Glycol is the solvent, and takes the place of water in a standard formula. The use of glycol permits the formulation of a developer with very low preservative content while simultaneously and significantly extending the shelf life of the concentrate.

To be clear, the formula is for a concentrated stock solution that is diluted with water to make a working solution. 1+5+94 (1:5:100) is a standard dilution.

Merry Christmas!

[onnect17]

Sandy and Jay,
I have some tmax 100 35mm I can use for testing Pyrocat-HD and 510-Pyro. Your guys are more than welcome to suggest temperature and developing time for a jobo. I can post a link to the raw images for discussion.
You can pick the scanner: Nikon CoolScan V ED, Imacon 343 or Howtek 4000.
Armando

[Jay DeFehr]

Armando,

I think Sandy and I are more than familiar with these developers and so there's little to be gained by your generous offer. If your curious about the differences, you should test for your own benefit. Let me know if I can be of any help.

[onnect17]

Sure, Could 1:100, 6 mins at 68F be a good starting point for 510-Pyro in the rotary?

Armando,

I think Sandy and I are more than familiar with these developers and so there's little to be gained by your generous offer. If your curious about the differences, you should test for your own benefit. Let me know if I can be of any help.