Reuse of Pyrogallol developer

Silverhalide Emulsions / Chemistry.
jrburns47
Posts: 164
Joined: Mon Sep 14, 2015 2:48 pm
Location: Oyster Bay, NY

Re: Reuse of Pyrogallol developer

Post by jrburns47 »

Hi Martin,
Thank you for taking the time to reply. The “acutance dye” being an anti-halation dye? When I was using the 3-step alcohol dry process many years ago in which I observed a pink hue left in the 50/50 bath, it was mostly with Agfa 8E56HD and Millimask plates.

I’m testing a possible new 660nm red laser and have four 4x5” plate materials available to me, 10E75NAH, 8E75, 8E75HD, and Ilford SP696T. All of these materials are at least 30-40 years old. In theory, all these materials are sensitive in the 660nm range.

The test shot is a white light viewable achromat (open aperture) H2 transfer tests from a 12x16” ruby pulsed H1 portrait.

My plan has been to use Pyrochrome processing for everything to start with and, once I have a baseline, move to Nick’s#5 (slightly different formulations for Ilford & Agfa) dev with FeEDTA followed by photoflo rinse. I dislike photoflo but my unscientific experience using SP695T with 532nm discouraged me from using alcohol drying with Ilford materials. I’d be very happy to go back to alcohol drying though and ditch the photoflo for transmission holograms.

So far, I’ve gotten surprisingly good results with the 10E75NAH (see photo). For some reason, after five tests, I’m getting absolutely nothing with SP696T plates. Just an all over even tanning of the emulsion side with not even plate holder occlusion area. Either it’s a bad box of plates, or it’s not at all sensitive to 660nm, or there’s something about the pyrochrome it doesn’t like. I’m going to do one more test with just Dev/fix this afternoon and, if nothing there, try another box. If still nothing, then I’ll move on to 8E75 tests. It would be a damn shame because I’ve got a lot of the old SP696T plates.

Looking at your last suggestion re Jeff B’s printout prevention bath, how would that compare to Ilford’s old recommended potassium iodide anti printout bath.

Ultimately my goal is the old very bright clear plates that “pop”😊😂.

Re attached photo, I know that I can get rid of wood grain by changing from s-pol to p-pol. Right now for testing, not necessary 😊.
Attachments
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Din
Posts: 401
Joined: Thu Mar 12, 2015 4:47 pm

Re: Reuse of Pyrogallol developer

Post by Din »

jrburns47 wrote: Sat Jan 15, 2022 10:56 am The only thing is, that the old 10E75 wants 10X normal exposure for bleaching with Pyrochrome. I’m guessing that the 10E75 must have a sensitizer for red laser light.
Correct. See below spectral sensitivity curve for 10E75 and also de variation on bleaching and not bleaching. This (https://www.osapublishing.org/ao/abstra ... -8-11-2353) paper may be of interest. I have access to the full paper.
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Din
Posts: 401
Joined: Thu Mar 12, 2015 4:47 pm

Re: Reuse of Pyrogallol developer

Post by Din »

I couldn't put the de curve on the previous post, so I'm putting it here.
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jrburns47
Posts: 164
Joined: Mon Sep 14, 2015 2:48 pm
Location: Oyster Bay, NY

Re: Reuse of Pyrogallol developer

Post by jrburns47 »

Thank you Dinesh. I’ve only got a few of the 10E75 plates but a lot of the old 10E75 film! Yes, please do forward the 1969 10E75 paper when you have a chance😊. For the most part, I never took 10E75 seriously - viewed it mainly as a teaching material. After my recent tests though, I have to change my opinion, especially compared to my non-results with old Ilford SP696T. Going to try a D-19/fix “last gasp” test on this box of SP696T 4x5” plates to eliminate the Pyrochrome processing as the issue. I found another box with a different batch number and will try that if no result w/ D-19/fix. What’s odd to me, is that the green SP695T has been great so far.
Din
Posts: 401
Joined: Thu Mar 12, 2015 4:47 pm

Re: Reuse of Pyrogallol developer

Post by Din »

jrburns47 wrote: Sun Jan 16, 2022 11:31 am Thank you Dinesh. I’ve only got a few of the 10E75 plates but a lot of the old 10E75 film! Yes, please do forward the 1969 10E75 paper when you have a chance😊. What’s odd to me, is that the green SP695T has been great so far.
I'm sending the paper. I don't know the Ilford material. I do know that we used Ilford material when I was at Applied Holographics, ca 1982. My memory is that the Ilford material was optimised for pulse lasers, since Applied's market was the Holoprinter that worked with the ruby laser. However, I would guess that the grain size of the red sensitive material may be larger than the green sensitive material. If so, I would hazard a guess that dark reaction would increase on the larger, red sensitive, material. This is because dark reaction is a surface phenomenon, and the larger the grain size, the greater the ratio between surface area and volume.
jrburns47
Posts: 164
Joined: Mon Sep 14, 2015 2:48 pm
Location: Oyster Bay, NY

Re: Reuse of Pyrogallol developer

Post by jrburns47 »

It’s a mystery to me. Attaching a photo of the SP696T sensitivity curve.
Attachments
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Din
Posts: 401
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Re: Reuse of Pyrogallol developer

Post by Din »

I'm afraid the sensitivity curve is not a lot of use in determining if dark reaction has printed out the film. One way of testing is to take a small piece and develop it without any light exposure. If it goes dark, then the culprit is dark reaction. If so, the film may be re-claimable; I recall a conversation between Martin and Jeff Blythe in which they talked of rejuvenating old film by using a rehalogenating bleach. If successful, the grain size will be smaller, so needing higher exposures. Perhaps Martin remembers.
Martin
Posts: 131
Joined: Sat Apr 04, 2015 2:36 am

Re: Reuse of Pyrogallol developer

Post by Martin »

jrburns47 wrote: Sun Jan 16, 2022 10:20 am The “acutance dye” being an anti-halation dye? When I was using the 3-step alcohol dry process many years ago in which I observed a pink hue left in the 50/50 bath, it was mostly with Agfa 8E56HD and Millimask plates.
I seem to remember that acutance dyes were different from AH dyes.They were used in photographic emulsions to improve image sharpness. In the context of holography and with relatively large AgX grains perhaps the idea was to lower stray light (scatter).

jrburns47 wrote: Sun Jan 16, 2022 10:20 am I’m testing a possible new 660nm red laser and have four 4x5” plate materials available to me, 10E75NAH, 8E75, 8E75HD, and Ilford SP696T. All of these materials are at least 30-40 years old. In theory, all these materials are sensitive in the 660nm range.
Interesting tests, please let us know...

jrburns47 wrote: Sun Jan 16, 2022 10:20 am So far, I’ve gotten surprisingly good results with the 10E75NAH (see photo). For some reason, after five tests, I’m getting absolutely nothing with SP696T plates. Just an all over even tanning of the emulsion side with not even plate holder occlusion area. Either it’s a bad box of plates, or it’s not at all sensitive to 660nm, or there’s something about the pyrochrome it doesn’t like.
That's weird. I would also have expected some reaction to 660nm. How about making an exposure with the unexpanded beam?
jrburns47 wrote: Sun Jan 16, 2022 10:20 amLooking at your last suggestion re Jeff B’s printout prevention bath, how would that compare to Ilford’s old recommended potassium iodide anti printout bath.
Regarding the level of scatter, it would perform much better.
Martin
Posts: 131
Joined: Sat Apr 04, 2015 2:36 am

Re: Reuse of Pyrogallol developer

Post by Martin »

Din wrote: Sun Jan 16, 2022 12:25 pm My memory is that the Ilford material was optimised for pulse lasers, since Applied's market was the Holoprinter that worked with the ruby laser. However, I would guess that the grain size of the red sensitive material may be larger than the green sensitive material. If so, I would hazard a guess that dark reaction would increase on the larger, red sensitive, material. This is because dark reaction is a surface phenomenon, and the larger the grain size, the greater the ratio between surface area and volume.
Another explanation would be that the "BIPS"-thing might have shortened shelf-life of the material (BIPS stands for "build-in-preswelling-substance" or something like that - similar to the triethanolamine pre-swelling) I think - as you said - the SP-696 was optimized for ruby pulse exposures. After processing, rehalo-bleaching, removal of the BIPS, the emulsion nicely played back at 633nm.
Martin
Posts: 131
Joined: Sat Apr 04, 2015 2:36 am

Re: Reuse of Pyrogallol developer

Post by Martin »

Din wrote: Sun Jan 16, 2022 5:36 pm One way of testing is to take a small piece and develop it without any light exposure. If it goes dark, then the culprit is dark reaction. If so, the film may be re-claimable; I recall a conversation between Martin and Jeff Blythe in which they talked of rejuvenating old film by using a rehalogenating bleach. If successful, the grain size will be smaller, so needing higher exposures. Perhaps Martin remembers.

That's a good point. I think the main issue is to get rid of the inherent fog on these old plates/films. I guess we've had several discussions about that subject on this forum. I recall Jeff mentioning inserting the AgX emulsion into a weak FeEDTA/KBr solution (something like 10g FeEDTA, 20g KBr per L). It turned out there was no need for an additional ascorbate re-activation step.
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