PYRO developing in a Jobo ATL-1000

Film Photography & Darkroom discussion

Moderator: Keith Tapscott.

Ornello
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Joined: Thu Jan 19, 2006 9:49 am

Post by Ornello »

Jay DeFehr wrote:I think there is a lot of confusion surrounding the effects of stained negs on VC papers, and a lot of it has to do with misconceptions about the way VC paper works. VC paper emulsions are made up three separate blue-sensitive emulsions, with varying sensitivities to green light. All of the layers are of equal contrast, and speed to blue light, but vary in their speed to green. This allows contrast to be controlled by the amount of green light relative to the amount of blue light that makes up the total exposure. The only question pertinent to stained negatives and VC papers is; how much printing density is added by the stain? Remember, printing density is created by the light that's blocked, and not the light that's transmitted. The yellow-green pyro stain is very effective at blocking/absorbing blue light, to which the paper is most sensitive, and thereby creates printing density. The green light that is transmitted by the stain exposes the far less sensitive, green-sensitive emulsion, reducing the net printing density created by the stain, to some extent, which is why stained negatives print with greater contrast on graded papers than on VC papers. It's that simple. Thinking of the pyro stain as a contrast filter is a misguided obfuscation. The pyro stain does not reduce contrast, not even in the highlights. The pyro stain adds printing density, which increases contrast with all papers, including VC papers. I hope this clears up some of the misconceptions regarding stained negs and VC papers propogated by some of the "experts".

Jay
You're agreeing with me, Jay.

The stain adds very little density that VC papers can see at 'normal' contrast filtrations (which pass a lot of green light), which is why the speed is poor. You're better off with a conventional developer for most purposes.

Jay DeFehr
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Joined: Tue Jan 24, 2006 8:40 pm

Post by Jay DeFehr »

Orny,

I am not agreeing with you. You maintain that pyro stain is "invisible" to VC paper, which it most certainly is not. I'll try to keep it very simple for you, pyro stain adds printing density with VC paper. I've written nothing about film speed, which is an entirely different subject, and has little to do with pyro stain, which is practically non-existent in the toe region of the film curve, where film speed is determined. Some pyro films give poor film speed, others produce ISO speed, or better. Your ignorance extends beyond staining developers and to basic photographic principles. You're not qualified to participate in this kind of discussion.

Jay

Ornello
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Post by Ornello »

Jay DeFehr wrote:Orny,

I am not agreeing with you. You maintain that pyro stain is "invisible" to VC paper, which it most certainly is not. I'll try to keep it very simple for you, pyro stain adds printing density with VC paper. I've written nothing about film speed, which is an entirely different subject, and has little to do with pyro stain, which is practically non-existent in the toe region of the film curve, where film speed is determined. Some pyro films give poor film speed, others produce ISO speed, or better. Your ignorance extends beyond staining developers and to basic photographic principles. You're not qualified to participate in this kind of discussion.

Jay
It is 'invisible' when there is a lot of green in the pack. Yes, it is.

I'm more qualified to participate in this discussion than you are, that's for sure. Anyone who would use pyro today with small format film on VC paer is totally insane. It's probably the worst possible combination imaginable. Read Edge of Drakness and see what the facts are. Small format film requires acutance developers that have surface action. VC papers require a single-color of deposit (silver) to work properly. Of all the obsolete things in photography, pyro is the most utterly obsolete thing there is. If you don't use Azo or other contact paper (Wait! there isn't any!) the stain is not 'seen' fully by the paper. It might as well not even be there. Graded enlarging papers have some green sensitivity. Contact papers had none.

Apart from its staining properties, pyro give a coarse-grained, low-acutance image. When the stain is added to the image, it tends to soften the apparent grain. But the stain is not 'seen' by VC papers at 'normal' filtration. Thus, the temptation is to increase developing time to create more silver deposit...which makes the grain even worse...

Jay DeFehr
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Post by Jay DeFehr »

Pyro stain is not invisible to VC paper. Repeat that to yourself until you understand. I don't even know what you mean by:
It is 'invisible' when there is a lot of green in the pack.
and I suspect that you don't either. Pyro developers have long been prized for their acutance characteristics. The tanning action hardens the emulsion in proportion to the exposure, reducing the migration of developer within the emulsion to increase apparent sharpness, without increasing apparent grain. Pyro also produces the most dramatic adjacency effects of any developing agent, further enhancing apparent sharpness. Your characterisation of Pyro illustrates your ignorance of the subject. I've read Thornton's book, and it is a good primer on the subject of acutance, but far from a definitive work. Did it totally escape you that Thornton formulated a staining developer specifically for its acutance characteristics? Regarding film speed, you clearly don't even know how it is determined, suggesting that the pyro stain somehow affects film speed, and it's even more obvious that you don't understand how VC papers work, when you state:
VC papers require a single-color of deposit (silver) to work properly
Saying it don't make it so, Orny. How about some support? I've explained as clearly as I'm able how VC papers work with stained negs, perhaps you could explain in similar detail why your statement above is true? While you're at it, can you explain how image stain affects film speed?

Everything you've written is absolute nonsense, and illustrates your complete ignorance of the subject. I recommend you re-read my previous post. Read it slowly, and repeatedly, until it begins to sink in. When you think you're beginning to understand, read it again. When you're sure you understand, try to address my questions above, and, if necessary, read my post again. If you ever do begin to understand, you'll probably feel pretty stupid; that's progress. When you realize that you're a complete moron, you're nearly there.

Jay

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Ornello
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Joined: Thu Jan 19, 2006 9:49 am

Post by Ornello »

Jay DeFehr wrote:Pyro stain is not invisible to VC paper. Repeat that to yourself until you understand. I don't even know what you mean by:
It is 'invisible' when there is a lot of green in the pack.
and I suspect that you don't either. Pyro developers have long been prized for their acutance characteristics. The tanning action hardens the emulsion in proportion to the exposure, reducing the migration of developer within the emulsion to increase apparent sharpness, without increasing apparent grain. Pyro also produces the most dramatic adjacency effects of any developing agent, further enhancing apparent sharpness. Your characterisation of Pyro illustrates your ignorance of the subject. I've read Thornton's book, and it is a good primer on the subject of acutance, but far from a definitive work. Did it totally escape you that Thornton formulated a staining developer specifically for its acutance characteristics? Regarding film speed, you clearly don't even know how it is determined, suggesting that the pyro stain somehow affects film speed, and it's even more obvious that you don't understand how VC papers work, when you state:
VC papers require a single-color of deposit (silver) to work properly
Saying it don't make it so, Orny. How about some support? I've explained as clearly as I'm able how VC papers work with stained negs, perhaps you could explain in similar detail why your statement above is true? While you're at it, can you explain how image stain affects film speed?

Everything you've written is absolute nonsense, and illustrates your complete ignorance of the subject. I recommend you re-read my previous post. Read it slowly, and repeatedly, until it begins to sink in. When you think you're beginning to understand, read it again. When you're sure you understand, try to address my questions above, and, if necessary, read my post again. If you ever do begin to understand, you'll probably feel pretty stupid; that's progress. When you realize that you're a complete moron, you're nearly there.

Jay

.
More nonsense is spouted about pyro than I have time or energy to disspiate. Everything you know about this topic is wrong (and I do mean everything), and I would appreciate it if you would educate yourself about a topic before writing about it here. Look at Edge of Darkness. The author shows you clearly (using two types of paper: graded and VC) how the stain does not print on VC paper. What else it would take to convince you that everything you know is wrong, I have no idea. Just don't bring it here, OK? This is a nice place. Let's keep it that way.

Keith Tapscott.
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Location: Plymouth, England.

Post by Keith Tapscott. »

When you realize that you're a complete moron, you're nearly there.

Jay.
This is a nice place. Let's keep it that way.[/quote]

Yes it is a nice place and name calling to one another isn`t helpfull. :oops:

Ornello
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Post by Ornello »

Keith Tapscott. wrote:
When you realize that you're a complete moron, you're nearly there.

Jay.
This is a nice place. Let's keep it that way.
Yes it is a nice place and name calling to one another isn`t helpfull. :oops:[/quote]

A complete explanation of how pyro-stain reacts with VC papers is available in the book Edge of Darkness by Barry Thornton. He shows prints made from the same negative on graded and VC papers, so anyone who takes the time and has an interest can see for himself.

Keith Tapscott.
Posts: 551
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Location: Plymouth, England.

Post by Keith Tapscott. »

I have a copy of that book, although mine is autographed by Barry himself. Another book that I have is called `Elements Of Transition` which he wrote inside: "To my freind Keith Tapscott" and again signed.
I haven`t taken that digital route myself though.

Jay DeFehr
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Joined: Tue Jan 24, 2006 8:40 pm

Post by Jay DeFehr »

Anyone who actually uses a staining developer can test for themselves to see how a stained neg prints on VC papers. I've printed thousands of them, myself. Everything I've written is absolutely true, verified by me, in real working conditions. The only reason I engage in any kind of discourse with the likes of Mike Scarapitti/ "Ornello", is for the benefit of those who might be follwing the thread, and be confused by his absolute ignorance of the subject, and willfull disemination of misinformation. Consider that the only support he's given for his arguments is his referrence to Thornton's book, with no details. I've explained very clearly how VC papers work, how they react to a stained neg, and why graded papers print stained negs differently than VC papers do. I hope my explanation is useful to those who have been curious or confused about the subject, and that Orny hasn't distracted too much from the subject with his inane chatter.

Jay

Ornello
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Joined: Thu Jan 19, 2006 9:49 am

Post by Ornello »

Jay DeFehr wrote:Anyone who actually uses a staining developer can test for themselves to see how a stained neg prints on VC papers. I've printed thousands of them, myself. Everything I've written is absolutely true, verified by me, in real working conditions. The only reason I engage in any kind of discourse with the likes of Mike Scarapitti/ "Ornello", is for the benefit of those who might be follwing the thread, and be confused by his absolute ignorance of the subject, and willfull disemination of misinformation. Consider that the only support he's given for his arguments is his referrence to Thornton's book, with no details. I've explained very clearly how VC papers work, how they react to a stained neg, and why graded papers print stained negs differently than VC papers do. I hope my explanation is useful to those who have been curious or confused about the subject, and that Orny hasn't distracted too much from the subject with his inane chatter.

Jay
To encourage anyone to use pyro today is close to a criminal act. Its heyday was long ago. Much better developers are available today. There is no conceivable reason for anyone to use pyro today. There are no benefits to using pyro. Is that clear enough for you?

Jay DeFehr
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Joined: Tue Jan 24, 2006 8:40 pm

Post by Jay DeFehr »

It's clear enough that you've never used a pyro developer, which doesn't make you much of an authority on the subject, does it? Why don't you stick to subjects with which you have at least a passing familiarity? Developers in general, and pyro developers in particular are way over your head. You should probably just stick with D-76 and use the development times printed on the box, if you actually have a camera.

Jay

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Post by Digitaltruth »

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