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#31
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Reformed Pyro Workers
"Gregory W Blank" wrote in becauzzzze if you run a sheet of film without exposure and process it in pyro there is still stain,... Yeah, I noticed that, but I didn't want to pen another off the wall technical treatise... Pyro is interesting in that you can fix and/or wash part or maybe all of the stain away by extending times.. It raises the question of what the stain molecule is actually bound to... At first blush it does not appear that it reacts with the reduced silver as an oxide, for if it were I would not expect that extended washing would have any major effect on stain density... It appears to me that the staining/binding is gelatin bound and is promoted in the areas where more silver bromide is being reduced, and there is a higher concentration of byproducts of that reaction... What is the mordant? Lots of interesting questions... Has anyone done an NMR on the stain to see what it's chemical structure is? Next order to PF I will get a bottle of pyro and soup a few 4x5 just to say I have done it once, and to have something to look at and ponder.. I'm leaning towards the W2D2+... Comments from the group? denny |
#32
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Reformed Pyro Workers
Dennis O'Connor wrote: "Gregory W Blank" wrote in becauzzzze if you run a sheet of film without exposure and process it in pyro there is still stain,... Yeah, I noticed that, but I didn't want to pen another off the wall technical treatise... Pyro is interesting in that you can fix and/or wash part or maybe all of the stain away by extending times.. It raises the question of what the stain molecule is actually bound to... At first blush it does not appear that it reacts with the reduced silver as an oxide, for if it were I would not expect that extended washing would have any major effect on stain density... It appears to me that the staining/binding is gelatin bound and is promoted in the areas where more silver bromide is being reduced, and there is a higher concentration of byproducts of that reaction... What is the mordant? Lots of interesting questions... Has anyone done an NMR on the stain to see what it's chemical structure is? Next order to PF I will get a bottle of pyro and soup a few 4x5 just to say I have done it once, and to have something to look at and ponder.. I'm leaning towards the W2D2+... Comments from the group? denny I can tell you that the simplest pyro developer I have made is 7 to 10 grams of pyro dissolved in 100 ml of triethanolamine. This single solution lasts and lasts. The TEA is an organic base that is not active until you add water. Dilute the Pyro-TEA 1+50 and it develops film in 10 to 14 minutes. You can get both ingredients at Photographer's Formulary. You must heat the TEA in order to dissolve the pyro before the end of the century, but it does not precipitate when it cools. If anyone wants to know, my email is |
#33
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Reformed Pyro Workers
"Dennis O'Connor" wrote in message ...
"Gregory W Blank" wrote in becauzzzze if you run a sheet of film without exposure and process it in pyro there is still stain,... Yeah, I noticed that, but I didn't want to pen another off the wall technical treatise... Pyro is interesting in that you can fix and/or wash part or maybe all of the stain away by extending times.. It raises the question of what the stain molecule is actually bound to... At first blush it does not appear that it reacts with the reduced silver as an oxide, for if it were I would not expect that extended washing would have any major effect on stain density... It appears to me that the staining/binding is gelatin bound and is promoted in the areas where more silver bromide is being reduced, and there is a higher concentration of byproducts of that reaction... What is the mordant? Lots of interesting questions... Has anyone done an NMR on the stain to see what it's chemical structure is? Next order to PF I will get a bottle of pyro and soup a few 4x5 just to say I have done it once, and to have something to look at and ponder.. I'm leaning towards the W2D2+... Comments from the group? denny I started the whole thing last year. Got incredible test shots with PMK, then went out and shot real scenes and got contrast up the ying yang. I never understood why. PMK requires considerable agitation to avoid streaking and I may have made my martini's a little too hard. In the interum I tried W2D2, and was taken aback by an even softer look than the PMK. I added B, and was pretty much back at the first PMK's, which satisfied my taste for long tones, atmosphereic, but vital scene contrast. That said for some reason, I did some Pyrocat too, and have stuck with that instead. Probably because it sounds cooler. So sue me. I use half the B solution giving me a 1:1/2:100 mix @ 70 degrees for 8 min. Works extremely well for me, but my times are always shorter than anyone else's. I give my HP-5 a 160 rating. The stuff is economical, doesn't have the agitation fuss of PMK, and like I said sounds cool. As for the washing discussion, I am not swearing by it, but have read, here, by many people, that washing increases the stain. Never use a hardening fixer, and some people even skip a hypo clear, and wash twenty min. in the belief that that also maintains the stain...in the rain Ken Smith Whereoming |
#34
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Reformed Pyro Workers
On Tue, 03 Feb 2004 15:16:32 -0800, Ken Smith wrote:
I may have gone overboard with the highlight controls of pyro developers. Originally I was a Tri-X, HC-110 landscape shooter, but came to feel that I was forever struggling to hold highlight/sky etc. snip The documentary/geological survey approach in all it's anti-scenic splendor. A sense of light/atmosphere is more the goal than an old fashioned knock your socks off graphic image with deep blacks and brilliant whites. Ken, First, what you are describing is the struggle to control Tri-X and HC-110's characteristic curve. This combination results in a "rising" curve (toe without shoulder),where highlights become ever more contrasty. This results in a really nice look, but is a pain to control, because you walk on the knife edge of blown highlights. One way to "solve" this problem, is to use a film/developer combination that results in more of a shoulder. One of the classic ways to do this is to use stand development with an acutance developer to create compensation. You can learn more about this from the recent classic "The Film Developing Cookbook" by Anchell and Troop. Another way to handle this, is to do something that is anathema to most everyone in this group. That is, print digitally. This can completely change the way you develop your negatives. Basically, instead of "expose for the shadows and develop for the highlights" you "expose for the shadows and scan for the highlights." In zone system parlance, you only use N development. You can drop all N- and N+ development, because you no longer have to shoehorn 10 or 11 stops of image brightness into eight zones. This works because the scanner is an intermediate step in the process. Your negative density is unlikely to be more than any modern scanner can handle. The scanner will take whatever the density range is on the negative and spread it uniformly out over a range of numbers (if you are scanning in 8 bit mode, that range is 0-255). Bottom line is no more blown out highlights. This isn't theory. I've been doing this with 4x5 Tri-X, XTOL 1:3, scanning, and printing with Epson printers using selenium tone Piezotone inks on Hahnemuhle Photo Rag for quite a while now. The prints show more shadow detail *and* more highlight detail than I ever got during 30 some years of dark room prints, and I'm not a bad darkroom printer. These inkjet prints are beautiful. Whether or not this is the right thing for you, only you can decide, YMMV, etc. However, it *can* end your problems with brightly lit scenes and blown out highlights. |
#35
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Reformed Pyro Workers
"hogarth" wrote in message news:pan.2004.02.10.00.05.30.284519@**notspam***s nappydsl.net...
On Tue, 03 Feb 2004 15:16:32 -0800, Ken Smith wrote: I may have gone overboard with the highlight controls of pyro developers. Originally I was a Tri-X, HC-110 landscape shooter, but came to feel that I was forever struggling to hold highlight/sky etc. snip The documentary/geological survey approach in all it's anti-scenic splendor. A sense of light/atmosphere is more the goal than an old fashioned knock your socks off graphic image with deep blacks and brilliant whites. Ken, First, what you are describing is the struggle to control Tri-X and HC-110's characteristic curve. This combination results in a "rising" curve (toe without shoulder),where highlights become ever more contrasty. This results in a really nice look, but is a pain to control, because you walk on the knife edge of blown highlights. One way to "solve" this problem, is to use a film/developer combination that results in more of a shoulder. One of the classic ways to do this is to use stand development with an acutance developer to create compensation. You can learn more about this from the recent classic "The Film Developing Cookbook" by Anchell and Troop. Another way to handle this, is to do something that is anathema to most everyone in this group. That is, print digitally. This can completely change the way you develop your negatives. Basically, instead of "expose for the shadows and develop for the highlights" you "expose for the shadows and scan for the highlights." In zone system parlance, you only use N development. You can drop all N- and N+ development, because you no longer have to shoehorn 10 or 11 stops of image brightness into eight zones. This works because the scanner is an intermediate step in the process. Your negative density is unlikely to be more than any modern scanner can handle. The scanner will take whatever the density range is on the negative and spread it uniformly out over a range of numbers (if you are scanning in 8 bit mode, that range is 0-255). Bottom line is no more blown out highlights. This isn't theory. I've been doing this with 4x5 Tri-X, XTOL 1:3, scanning, and printing with Epson printers using selenium tone Piezotone inks on Hahnemuhle Photo Rag for quite a while now. The prints show more shadow detail *and* more highlight detail than I ever got during 30 some years of dark room prints, and I'm not a bad darkroom printer. These inkjet prints are beautiful. Whether or not this is the right thing for you, only you can decide, YMMV, etc. However, it *can* end your problems with brightly lit scenes and blown out highlights. Thanks, I'd love to go full on scan,shop,inkjet, but I don't have the coin. I took a terrible career path money wise.Photography and painting! Art and time wise, I'm better off than millionairs. My pyro negs are looking good, and HP-5 has a better shoulder than the old Tri-x, don't know about the new. Other than that, given the cost of 8x10, I loaded holders with some RC paper the other day, and poped out one of the sweetest prints I've done if a long time. I couldn't believe it, tones and sharpness were all there, for 30 cents a negative. I'll have to go that direction for now. Find out what it can and can't handle, but wowie, what a feeling of liberation to shoot without cringing. |
#36
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Reformed Pyro Workers
"hogarth" wrote in message newsan.2004.02.10.00.05.30.284519@**notspam***sn appydsl.net... The prints show more shadow detail *and* more highlight detail than I ever got during 30 some years of dark room prints, and I'm not a bad darkroom printer. These inkjet prints are beautiful. The real concern, though, is how they will look in ten years. And twenty. And fifty. Well-processed black and white prints have an estimated life of centuries (as long as 500 years by some estimates). Some inkjet companies claim a century or more, but there are no century-old inkjet prints yet, and very few inkjet printers have that kind of capability. This needn't be a fatal flaw, but it is a major one. Jim |
#37
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Reformed Pyro Workers
"Jim MacKenzie" wrote
"hogarth" wrote The [ink jet] prints show more shadow detail *and* more highlight detail than I ever got during 30 some years of dark room prints... The real concern, though, is how they will look in ten years. And twenty. And fifty. Well-processed black and white prints have an estimated life of centuries ... No problem: Make archival copy negatives from the ink-jet print. I think the solution is a dodge & burn program on PhotoShop that spits out a mask that is placed above the negative for contrast & tone correction. -- Nicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. |
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