Improved pyro-ascorbic developer

sanking · May 22, 2005

Kirk Keyes said:
Sandy - you know I'm very interested in improving testing methods, and I'm sure many othere here are as well. Could you take this opportunity to expound on this subject some more - what other types of improvements have you made? I'm sure if more of us were using the same, if not at least similar, testing methods, we would have fewer of these issues.

So could you share some more ideas that you have to help improve film/paper testing?

(PS - I suspect the light integrator you are talking about is one of those exposure timers that has a light sensor built into it, and not some sort of diffusion panel to better disperse the light that you are using to make the test exposure with, right?)

Kirk

I will write up a summary of my testing procedures, but it will take a little time to do. I don't want to leave something out, and in an area like this incomplete information and knowlede can be be more dangerous than no information or knowledge.

By light integration, yes, I do mean a light sensor proble that reads the actual amount of light available during exposure, and cuts it off when the amount has been reached. This technology is widely used in the pre-press industry with plate makers. The use of a light integrator is useful in many aspects of film testing, but it is almost essential if one expects to observe and record meaningful differences in effective film speed.

Sandy

Kirk Keyes · May 22, 2005

sanking said:
I will write up a summary of my testing procedures, but it will take a little time to do. I don't want to leave something out, and in an area like this incomplete information and knowlede can be be more dangerous than no information or knowledge.

Sandy - thanks! I look forward to reading it. Perhaps it is something that you could get Unblinkingeye.com to host so it will not be lost in the depths of a forum thread.

Certainly be as explicit as possible as I agree about incomplete info - while it may not be exactly dangerous, it can certainly be a big time waster!

Kirk

gainer · May 22, 2005

I can say what I would like to see when comparisons are made of staining developers with each other or with non-staining developers. I would like to see some kind of measured paper scales made by contact printing the negatives of step wedges on, say, AZO, a graded bromide or chlorobromide paper, and a polycontrast paper. This would require measurements of reflection density, I suppose.

I do not mean to imply that the transmission densities through various filters are useless. I just think such comparisons might mean more to some among us who do not have the necessary densitometers nor the money to invest in them. Perhaps a simple statement of the way the number of density steps printable on each type of paper from the same negative will suffice. The nominal density range of the original step wedge establishes the equivalent of a scene log brightness range that would be printable on a given paper from a negative developed by the process under test.

gainer · May 22, 2005

Well, that was a little garbled. I hope you know what I meant to say.

Kirk Keyes · May 22, 2005

gainer said:
Well, that was a little garbled. I hope you know what I meant to say.

I think I got it, Pat.

sanking · May 22, 2005

gainer said:
I can say what I would like to see when comparisons are made of staining developers with each other or with non-staining developers. I would like to see some kind of measured paper scales made by contact printing the negatives of step wedges on, say, AZO, a graded bromide or chlorobromide paper, and a polycontrast paper. This would require measurements of reflection density, I suppose.

I do not mean to imply that the transmission densities through various filters are useless. I just think such comparisons might mean more to some among us who do not have the necessary densitometers nor the money to invest in them. Perhaps a simple statement of the way the number of density steps printable on each type of paper from the same negative will suffice. The nominal density range of the original step wedge establishes the equivalent of a scene log brightness range that would be printable on a given paper from a negative developed by the process under test.

In my experience the measured transmission density through blue filter for graded silver paper, including AZO, and UV for alternative processes, provides a reliable indicator of the ES of these processes. However, if you really want to match the process ES to the transmission density you need to also read the reflection densities and plot the curve. It is not easy to interpret a print made from a step wedge because of the very pronounced toe and shoulder of silver papers. This is obviously much easier with AZO and alternative processes that have longer straight line parts of the curve.

VC papers are another matter. When printing with stained negatives one simply much must print the step wedge, and in fact, with every one of the contrast filters, to have an accurate idea of the paper ES for a given filter. Trying to figure this out with transmission readings will provide at best some degree of approximation.

However, I have simplified my own life by printing with only AZO and alternative processes , so I will leave the issue of sensitometry in printing stained negatives with VC papers to others. But it is a very complicated issue, at least from the perspective of sensitometry.

Sandy

sanking · May 22, 2005

Kirk Keyes said:
Sandy - thanks! I look forward to reading it. Perhaps it is something that you could get Unblinkingeye.com to host so it will not be lost in the depths of a forum thread.

Certainly be as explicit as possible as I agree about incomplete info - while it may not be exactly dangerous, it can certainly be a big time waster!

Kirk

Kirk,

That is a good idea for a short article, and I am very confident that Ed Buffaloe would be willing to host it at his site. I feel certain that many people who are engaged in testing films and developers, for whatever purpose, could profit from the information.

And having the information out there would save me a lot of time since I will be able to direct people to the site.

Unfortunately, it will probably be late summer before I will be able to get around to this. At the moment I am very involved in writing an introduction on landscape photography for a friend in Spain who is publishing a book of his photographs, and at the beginning of June I am headed out west for about 1.5 months.

sanking · May 22, 2005

BTW, although I have been critical of Jay in some areas, I do want to compliment him for the 510-Pyro formula. Although I have not actually tested 510-Pyro it looks to be a quite elegant formula and should give results at least equal to any of the other pyrogallol based devlopers out there.

Sandy

Kirk Keyes · May 22, 2005

sanking said:
Unfortunately, it will probably be late summer before I will be able to get around to this.

That sounds fine - it will give you something to do while you are sitting out the monsoons that occasionally roll through!

fhovie · Jun 26, 2005

After mixing the earlier wrong formula with a one stop loss in film speed, I just tried the new batch with the correct ammount of Phenidone and it looks very promising. It appears I have a density curve I can live with.

1:100 510 Pyro - TMAX 400 120 shot at 400
8 minutes at 70F aggitation every 30 seconds for 5 seconds
presoak .

Stain - on the order of PMK
Grain - on the order of Pyrocat (much finer than PMK)
Speed - FINNALY A STAINING DEVELOPER WITH FULL FILM SPEED FOR ROLL FILM!
Convenience - long shelf life simple single mix - Great
Highlight clamping - what PC-TEA did not do - but what Pyro formulas all seem to do.
Sharpness - like P'cat
The reason I was so interested in 510 Pyro is that p'cat and PMK cost me a stop - I have been looking for a full speed pyro for a while. I liked a lot of things about PMK but not the coarse grain for roll film. I like p'cat but hate the loss in in speed. (I didn't try hypercat) I really like the single TEA media - it is simple, elegent, inexpensive and it seems to cross the gap with all the benefits of PMK - PC-TEA and P'Cat. I believe P'cat will still be my choice for sheet film - It NEVER lets me down. I shoot mostly sheet film, but I like this 510 Pyro -
Looks like my new roll film developer.

Thank you Sandy for the giving us p'cat
Thank you Jay for the new invention

fhovie · Jun 26, 2005

I figure I got about 8 stops at that time (8 minutes 1:100 at 70F TMAX 400 at 400) - I think 10 minutes would give nicer contrast for normal shooting (also the film could probably be rated at 800) at 8 minutes I did not loose anything even down to zone 2. i am wondering about FP4 times and TRI-X times.

john_s · Jun 26, 2005

Forgive me if I've missed some of the instructions, but can you tell me if it dissolves easily in TEA? I have an aversion to the heating that's necessary with glycol developers.

Also, earlier in this thread there was some mention of a hump in the characteristic curve. Has that been found to be a real hump, or just an artefact of the measuring process?

fhovie · Jun 26, 2005

I heat the TEA in a microwave to 230 F - everything dissolves nicely at that temp. I don't know that it was mentioned in this thread.

Some clarification on the results of my above mentioned test:
BF .18 (Expired Film)
Zone 2 at .25 (approx)
Zone 8 at 1.25 (approx) - average density range 1.0 (361t ortho channel)
Film rated at 400 and it was a little flat on my grade 2 FB paper (wants 1.25 range)
Unless I am going to shoot very contrasty scenes, I will probably go with 9.5 minutes and see if I can get a working range for the average scene to be 1.25 for zone 8 - zone 2. The other option (maybe a better choice) is to develop for 45 minutes with agitations every 9 minutes (at 0.67:100)- that should give me almost double the film speed (800) and stretch the range out for 6 stops. I am hoping this will increase accutance.

fhovie · Jun 26, 2005

I just tried push processing - The results are not good - I tried 14min at 1600 ASA - Very thin - I was hoping to replace xtol for push processing. This one is not the one. I also tried partial stand - 45 min with 4 aggitations every 9 minutes - also not good - rated the film at 800 and it is also very thin - SBR of 4 or 5 - the film is still drying.

MikeS · Jun 27, 2005

Hi All.

I just mixed up some of the 510-Pyro, so does anyone have any idea of starting development times for EDU/J&C 400 film? If I've read the thread correctly it's diluted 1:100 (or 10ml stock to 990ml water to make a liter)?

Jay, any chance of getting a simple chart of film/dev times? I've yet to figure out all this stuff with charts, etc, and work better when I have starting times to work from. Thanks!

-Mike

gainer · Jun 27, 2005

fhovie said:
I just tried push processing - The results are not good - I tried 14min at 1600 ASA - Very thin - I was hoping to replace xtol for push processing. This one is not the one. I also tried partial stand - 45 min with 4 aggitations every 9 minutes - also not good - rated the film at 800 and it is also very thin - SBR of 4 or 5 - the film is still drying.

Don't be limited to 1:100 dilution. Try 1:50 or even 1:25. With a pyro developer with little or no sulfite, aerial oxidation may occur at a faster rate than development, thus limiting the contrast one can get. Trying to "push" by extended development may not be as effective in this case as increasing concentration in the working solution.

fhovie · Jun 27, 2005

TMY 70F 1:100 9 minutes
FB+F .17
1 .19
5 .65
10 1.24

good for grade 3 - I'll see if 60 sec more gives me a DR of 1.25

fhovie · Jun 27, 2005

I tried 2:100 for 9 minutes and exposed the TMY at 1600 and all the densities are exactly 2 stops down - It is as if I had done nothing different. - I had expected some push that could be seen at zone 5 but the zone 7 densities for the film at 1600 are the same as the densities at 400 at zone 5

fhovie · Jun 28, 2005

Here are the times and data for TMAX400 for 510 Pyro:

all for 70F and 5 sec agitation each 30sec
ASA Dilution SBR DR Time
400 1:100 10 1.0 9min
800 2:100 7 1.0 10min
1600 2:100 6 1.0 14min
These are good starting times - I like a DR of 1.25 for grade 2 but these will all print well.

fhovie · Jul 20, 2005

FP4 Results in 510 Pyro - WOWOWOWOW

OK - I am pinching myself here

ASA200! from FP4! Really

510 Pyro - 1:100 70F 7.5 min 5 sec aggitation every 30 sec

SBR 9 - DR 1.3
Zone Density - Ortho
BF+F .18
1 .23
2 .30
3 .40
4 .50
5 .76
6 .92
7 1.1
8 1.27
9 1.49

Non linearity might be my Old Yashica Shutter - else - I'd take this combo to the bank - I have always struggled to get ASA 80 out of FP4 and now I can get 200 without compression. AND - with all the benefits of pyro! -

fhovie · Jul 21, 2005

J&C 100 Film Test

J&C 100 at ASA 100
510 Pyro at 70F 8.5 minutes

Zone Density
1 .11
2 .16
3 .27
4 .44
5 .56
6 .76
7 .95
8 1.19
9 1.4
10 1.45

FB+F .09
SBR 9 DR 1.3

fhovie · Jul 21, 2005

APX 100 Film Test

APX 100 in 510 Pyro at 70F 8.5 Minutes

Agitation for all is 30sec then 5 sec every 25 sec

Zone Density
1 .20
2 .27
3 .40
4 .58
5 .74
6 .90
7 1.13
8 1.38
9 1.57
10 1.73

FB+F .16
SBR 8 DR 1.22

john_s · Jul 23, 2005

Jay, do I remember correctly that you were considering a formula like 510-Pyro but using pyrocatechol instead of pyrogallol? I'm interested in trying it, if you haven't, particularly since I have the ingredients but no pyrogallol. Would you suggest as a first attempt just substituting the pyrogallol with pyrocatechol in the same amount?

john_s · Jul 25, 2005

Further to my post above, I have looked around and found that TEA on its own has not a high enough pH for pyrocatechol. How would it go if I made Pyro-510 with pyrocatechol instead of pyrogllol, and then used, say, 1 part/100 of 750g/mL potassium carbonate as part_B. Are TEA and carbonate ok together?

gainer · Jul 25, 2005

john_s said:
Further to my post above, I have looked around and found that TEA on its own has not a high enough pH for pyrocatechol. How would it go if I made Pyro-510 with pyrocatechol instead of pyrogllol, and then used, say, 1 part/100 of 750g/mL potassium carbonate as part_B. Are TEA and carbonate ok together?

Jay has published a formula of that type somewhere in APUG and in the AZO forum that he calls Hypercat, IIRC.

Last night, I tried catechol-phenidone in glycol (same as Pyrocat without bisulfite, etc.) with a small amount of ascorbic acid in TEA with TEA as the separate activator. I started with 1+50 of the catechol and added 1/10 the amount of the ascorbate stuff plus TEA at about twice the volume of the catechol stuff. The negs were thin and practically unstained after 12 minutes at 75 F.

Improved pyro-ascorbic developer

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