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Photo Forum / Film Photography / Darkroom / December 2004Light source for Pyro negs
I'm not yet experienced with Pyro development, but I'm considering to give it a try. My questions concern the enlarger lamp for pringing pyro negatives. I read frequently that a cold light head is best for pyro negatives (presumably due to the yellowish stain on the neg), but I have a standard tungsten halogen lamp in my only enlarger, an Omega D2 with Super Chromega color head. I hope to use VC paper (Forte and Kodak). If the spectrum really must be close to that of a cold light head, is there a filtration offset that can be dialled into on the enlarger's color head to closely simulate the spectrum of a cold light lamp? Or, with regard to pringint pyro negs, is the spectral difference between cold light and tungsten halogen too small to be concerned about? Regards, Szabo > I'm not yet experienced with Pyro development, but I'm considering to give > it a try. My questions concern the enlarger lamp for pringing pyro > negatives. I read frequently that a cold light head is best for pyro > negatives (presumably due to the yellowish stain on the neg), but I have a > standard tungsten halogen lamp in my only enlarger, an Omega D2 with Super > Chromega color head. I hope to use VC paper (Forte and Kodak). The Chromega is perfectly fine. > If the spectrum really must be close to that of a cold light head, is there > a filtration offset that can be dialled into on the enlarger's color head > to closely simulate the spectrum of a cold light lamp? Or, with regard to > pringint pyro negs, is the spectral difference between cold light and > tungsten halogen too small to be concerned about? You can use the standard Poly Contrast filter values. Or seamlessly adjust by varying the Yellow and or Magenta. 7y + 21m = Grade 2 etc.  SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 >> I'm not yet experienced with Pyro development, but I'm considering to give >> it a try. My questions concern the enlarger lamp for pringing pyro [quoted text clipped - 4 lines] > > The Chromega is perfectly fine. Good. I'm not prepared to shell out good money for yet another contraption (in this case, a cold light head). >> If the spectrum really must be close to that of a cold light head, is there >> a filtration offset that can be dialled into on the enlarger's color head [quoted text clipped - 6 lines] > > 7y + 21m = Grade 2 etc. Thanks for the response. Cheers, Szabo > Thanks for the response. > Cheers, > Szabo Your welcome, and its good to be able to help someone that appreciates it. Feel free to stop back :-) SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 > I'm not yet experienced with Pyro development, but I'm considering to give > it a try. My questions concern the enlarger lamp for pringing pyro [quoted text clipped - 11 lines] > Regards, > Szabo Yes I think the spectral difference of the light source would be a fairly minor consideration, unless hairsplitting the science is more interesting that making pictures to you. The stain of a pyro neg acts as a low contrast filter, for the highlights with VC paper. I don't think it has any effect on graded paper. The standard tungsten light source is contrastier than a cold light, so your move to pyro would definitly smooth out the tonal range. I think you'll love the look. My landscapes have taken on a far smoother, more realistic and atmospheric quality. Enjoy. >> I'm not yet experienced with Pyro development, but I'm considering to give >> it a try. My questions concern the enlarger lamp for pringing pyro [quoted text clipped - 20 lines] > think you'll love the look. My landscapes have taken on a far > smoother, more realistic and atmospheric quality. Enjoy. I shall. And thanks for the response. I've seen some impressive prints made from pyro negs, but as Mr. Knoppow points out, this may be due, at least in part, to the printer being more meticulous with the process. I'll keep all this good advice in mind as I dabble with the new (for me) process. Cheers, Szabo >> I'm not yet experienced with Pyro development, but I'm considering to give >> it a try. My questions concern the enlarger lamp for pringing pyro [quoted text clipped - 20 lines] > think you'll love the look. My landscapes have taken on a far > smoother, more realistic and atmospheric quality. Enjoy. I shall. And thanks for the response. I've seen some impressive prints made from pyro negs, but as Mr. Knoppow points out, this may be due, at least in part, to the printer being more meticulous with the process. I'll keep all this good advice in mind as I dabble with the new (for me) process. Cheers, Szabo > I'm not yet experienced with Pyro development, but I'm > considering to give [quoted text clipped - 21 lines] > Regards, > Szabo Pyro developers produce a stain image that acts to intensify the silver image. The printing contrast is higher than the visual contrast. The stain image is yellowish and blocks blue light. Its effect depends mostly on the spectral sensitivity of the paper. Most cold light heads are quite blue, although there are some that approximately duplicate tungsten light for use with variable contrast filters. I think the idea that the cold light head is preferable comes from this. However, if the paper sees only blue light the spectral output of the printing light doesn't matter. Now, when variable contrast paper is used with pyro negatives there is some tendency for the stain image to act as a contrast reducing filter for the highlights. This may or may not be desirable since low contast highlights make prints look flat. The spectral distribution of the printing light will make some difference if VC paper is used the lack of green light tending to _increase_ contrast. Note that the low contrast filters for variable contrast paper are yellow while the high contrast filters are magenta. Yellow blocks blue light, magenta blocks green. All this is getting away from the point. If you print on graded paper the spectral content of the printing light will make little difference because the paper has a relatively limited spectral sensitivity which is centered in the range where the Pyro stain image is most effective. Blue cold light heads screw up variable contrast filtering anyway. Color heads and condenser heads are quite suitable for Pyro negatives. Just don't expect magic. I suspect many who rave about Pyro are getting better negatives because they are paying more attention to controlling all the variables. Signature--- Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com > Color heads and condenser heads are quite > suitable for Pyro negatives. Just don't expect magic. I > suspect many who rave about Pyro are getting better > negatives because they are paying more attention to > controlling all the variables. Understood. Thanks for the detailed and interesting response. As for pyro negs getting more attention, I see your point and agree. But maybe some of us could use the lesson in discipline. ;) Cheers, Szabo > I'm not yet experienced with Pyro development, but I'm considering to give > it a try. My questions concern the enlarger lamp for pringing pyro [quoted text clipped - 15 lines] > http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups > ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- The 'benefit' of a stained negative is the stain, which takes the place of silver density for papers that are sensitive only to blue. The stain is yellowish-green, and since these stains block blue light, they are seen as extra density by blue-sensitive paper. Variable contrast paper DOES see 'green', and so the stain DOES NOT act as density for VC papers. Use and GRADED paper to get the 'benefits' of pyro. The light source does not matter so much. DO NOT use VC paper, because it defeats the whole purpose of pyro. The stain is without grain and has a nicer gradation of tone than silver has, but again, only for graded (blue-sensitive) paper. A negative correctly developed in pyro has a rather 'thin' silver base which the stain supplements. If the stain were to be removed, the silver density of a properly-developed pyro negative would be seen as too flat and thin. It's supposed to be that way, because the stain assists in providing enough PRINTING density to give a good print. > The 'benefit' of a stained negative is the stain, which takes the > place of silver density for papers that are sensitive only to blue. [quoted text clipped - 6 lines] > does not matter so much. DO NOT use VC paper, because it defeats the > whole purpose of pyro. This information is completely wrong. > > Use and GRADED paper to get the 'benefits' of pyro. The light source > > does not matter so much. DO NOT use VC paper, because it defeats the > > whole purpose of pyro. > > This information is completely wrong. Consider the source,...and I don't mean light. Unless your equating light with dimly lit :-) SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 > Consider the source,...and I don't mean light. Unless your equating > light with dimly lit :-) Dimly lit. Yes, it just may be his lights are on but nobody is home... > > The 'benefit' of a stained negative is the stain, which takes the > > place of silver density for papers that are sensitive only to blue. [quoted text clipped - 8 lines] > > This information is completely wrong. No, it's correct! FACT: the stain is yellowish-green FACT: the stain TRANSMITS yellowish-green and STOPS blue light FACT: graded paper is insensitive to green or yellow light FACT: VC paper is sensitive to green light CONCLUSION: the stain ADDS density as far as graded paper is concerned, and DOES NOT add density as far as VC paper is concerned. In addition, the green light that the stain allows through softens the contrast in the most-heavily-exposed areas, precisely the opposite effect that occurs when graded paper is used. Attempting to use VC filtration to raise the contrast simply ignores the stain again, and you end up fighting against the stain. >> > The 'benefit' of a stained negative is the stain, which >> > takes the [quoted text clipped - 41 lines] > again, and > you end up fighting against the stain. It does add density for the blue sensitive component of variable contrast paper but less for the blue and green sensitive layer. This has the effect of modifying the characteristic curve of the paper. It creates what is effecively a shoulder which flattens highlight density. This may or may not be desirable. Some claim to get better prints this way. It probably depends on the subject matter as much as anything else. Essentially, the stain image acts as a mild contrast reducing mask when used with variable contrast paper. When used with graded paper the stain image simply adds to the silver image. This is not an advantage or disadvantage although it makes measuring the effective density of the iamge more difficult since the densitometer must have a filter which matches the spectral response of the printing material. I am not sure about the validity of the idea that the stain image masks grain since it must mimic the grain. Any diffusion of the stain away from the grains where it is generated would affect resolution and sharpness. This is not a common effect of Pyro development. Pyro developers also harden or tan the gelatin in a way which is proportional to the image density. This effect is used to produce relief images for dye transfer and other printing methods. In ordinary negatives it sometimes acts to increase acutance by modifying the diffusion rate at the edges of the image. The hardening itself can cause some increase in acutance because of the bending of light at the edge where the density of the gelatin is different. This differential hardening can also cause minor image distortion. This is of no consequence in normal photography but precludes the use of staining Pyro developers for photgrametry and astrophotography. Pyro is the oldest organic developing agent known. It was first used by F.Scott Archer C.1865 and has been in use ever since. Pyro fell out of use in the 1920's when Metol and Hydroquinone developers were devised. These were more predictable and more stable. Modern Pyro formulas are reasonably predictable but not very stable (PMK seems to be an exception). It is not very well known that Pyro developers also can be used for paper development to obtain warm tones. The stain image is not a dye but rather a very stable pigment, probably longer lived than the silver image. Signature--- Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com > > [quoted text clipped - 35 lines] >you end up fighting against the stain. > It is quite obvious that you have not tried it, and that you have not reasoned out the answer that you did not try. The yellow stain is a variable density stain. You can bleach out the silver image and leave a yellow IMAGE, not a filter layer. This yellow image can be printed on VC paper by use of sufficient blue filtering. I have done it, and several years ago demonstrated it in an article in Photo Techniques titled "More Pyrotechnics" . Certainly, the yellow image is of quite low contrast when printed on unfiltered VC paper, but it is there. The yellow part of an unbleached pyro negative DOES increase the contrast on VC paper, though not as much as on graded paper. If you do the following experiment, you will see the fallacy in your reasoning. Develop any negative in any non-staining developer to a lower than normal contrast index. Make a straight print without filtration on VC paper. Now bleach the negative in a rehalogenating solution such as is used in sepia toning, and redevelop it in a pyro staining developer. Make a straight print from this negative without filtration. Now make another print using magenta filtration or a #3 or #4 printing filter. Report to us the results if you dare. Uranium Committee wrote: It is quite obvious that you have not tried it, and that you have not reasoned out the answer that you did not try. Pat, I believe you have hit the nail on it's head. He has NEVER tried it and is going on his flawed deductive reasoning. I believe in an older post he said something like "... no I have never used pyro but have seen prints from negatives developed in pyro." Jim >>>>The 'benefit' of a stained negative is the stain, which >>>>takes the [quoted text clipped - 77 lines] > Report to us the > results if you dare. Its possible to bleach out either the stain or the silver image. The stain can be removed by using a permanganate type bleach. The stain image, as pointed out Patrick, acts as a proportional intensifier. Its density in relation to the silver density varies with the type of developer and the type of film. The ratio of densities can also be measured by making separate readings though the red and blue status filters of a color densitometer. The red filter will measure the silver image density along, the blue will measure both. The important thing is that there is no change in film characteristic, i.e., the _shape_ of the exposure vs: density curve from Pyro, only a change in its _effective_ overall slope. You could also prove this by printing on panchromatic paper trough red and blue filters. In the case of variable contrast paper it is possible that the yellow stain image causes a reduction of contrast as the density increases. I have never seen actual densitometric measurements of this so I can't say whether it is a reall or only a claimed effect. To be blunt I think Pyro is something of a fad. Pyro was the most used developer into the early 20th century but fell out of use when other, and better, developers became available. Signature--- Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com > To be blunt I think Pyro is something of a fad. Pyro was > the most used developer into the early 20th century but fell > out of use when other, and better, developers became > available. Well I am sure that could be among the unwashed masses. I've been using Pyro developers since the early 1990's maybe mid 1980's well before Gordon Hutchings published his book. There are also other photographers who have a much longer history than myself Michael A Smith, Steve Simmons probably a whole slue of others. I probably would have given up on Pyro had Gordon not devised the PMK formula, and had others not made other improvements in the Formula aka (Rollo PMK). The fade could be a result of f a reinsurgance of interest in the roots of photo, people's interest in Alt process as Pyro stained negatives have merits towards those applications. I personally became interested in Albumen printing and alt process as a result of my college history of photo course, I read the Keepers of Light and was some what intrigued by some of the old process. Around 1988 I did some basic experiments in creating salted prints paper negatives, it was a little before you heard so much of people doing such things. Its the fun side of photography so I doubt it will readily die out. SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 > > To be blunt I think Pyro is something of a fad. Pyro was > > the most used developer into the early 20th century but fell [quoted text clipped - 22 lines] > paper negatives, it was a little before you heard so much of people doing such > things. Its the fun side of photography so I doubt it will readily die out. Richard has often stated that pyro is probably a fad, or people are getting good effects because of an increased amount of attention paid. All I can say is after many years of regular developers, resulting in highly diluted developers to control landscape contrast, I tried pyro (cat) and was finally happy with the look of things. I could maintain alot of shadow detail, yet still have a nice atmospheric sky, even though the exposures usually favor the shadow. My skies would often white out with regular developers. Less dev. times and the scene goes flat and looks like a compensating developer or preflash was used. The powerful Ansel Adams look often settles for darker shadows, as the image made is more theatrical than I'm making. Weston too, has than drama. I'm more interested in how the eye sees the contrast, and really have to fight for longer tones. Although they both have many shots where it all comes together, I tend to think thats due to lighting conditions more than anything else. With my dev. time using pyrocat, I have found where I can get a long tonal range while still maintaining a perfect contrast. Never flat looking and IMO more natural looking than regular developers. If I want the punchier graphic look, I stick with D-76, but pyrocat definitly yeilds a unique and natural looking image. More like what the eye sees. 1:100 Rodinal, highly diluted HC-110, etc, will deaden into flatness if I reduce the development enough to hold the high areas the way the pyro does. I would say that because I give a full shadow exposure, even in contrasty light, my highs get way up there, so the stain allows good printability but is still a pleasing white. Detail without drabness. Ken Smith > > [quoted text clipped - 120 lines] > > Pyro does have advantages for those who would like to be able to use the same negative for either printing-out processes that require high contrast but are only blue sensitive or printing with VC paper. There are also advantages claimed for wide range scenes that include clouds. I have been privileged to have a compilation of the papers of Hurter & Driffield who considered and experimented with inorganic developer and organic pyrogallol. They never made much of the staining by pyro, using enough sulfite to pretty well eliminate the stain. My point, with which I think you agree, is that the effect of the pyro stain when properly done is to increase the contrast even with VC paper, though not as much as with graded paper, and to present some experiments to demonstrate it. I do not use a lot of staining developer, but do occasionally use it as an intensifier to increase contrast of underveveloped negatives. I guarantee it works, and the process may be repeated. Each repetition restore the original silver density and adds to it a proportional stain. ><big snip> > To be blunt I think Pyro is something of a fad. Pyro was > the most used developer into the early 20th century but fell > out of use when other, and better, developers became > available. True, but that was before PMK, which turned pyrogallol based developers into a reliable method of development. Our gratitude to Patrick Gainer for that. Francis A. Miniter > ><big snip> > > To be blunt I think Pyro is something of a fad. Pyro was [quoted text clipped - 6 lines] > > Francis A. Miniter Patrick? Is there some connection between our Patrick and Gordon Hutchings work that I am unfamilar with, of course there could be because I don't pretend to know all, but now I am curious. SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 >>><big snip> >>> To be blunt I think Pyro is something of a fad. Pyro was [quoted text clipped - 10 lines] > Gordon Hutchings work that I am unfamilar with, of course there > could be because I don't pretend to know all, but now I am curious. That's the problem with rushing. I meant Gordon Hutchings and had just looked at Patrick's name in a previous post. Sorry. Francis A. Miniter >>>> <big snip> >>>> To be blunt I think Pyro is something of a fad. Pyro was the most [quoted text clipped - 15 lines] > > Francis A. Miniter Well, that solves that mystery. I was beginning to think I was better thn I am. > Gregory W Blank wrote: > > [quoted text clipped - 4 lines] > That's the problem with rushing. I meant Gordon Hutchings and had just looked > at Patrick's name in a previous post. Sorry. > Francis A. Miniter As I suspected :-) SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 : ><big snip> : > To be blunt I think Pyro is something of a fad. Pyro was [quoted text clipped - 4 lines] : True, but that was before PMK, which turned pyrogallol based developers into a : reliable method of development. Our gratitude to Patrick Gainer for that. I'd like to add that while I've never used pyro or pmk I know people that do. The results that they get is impressive. SignatureKeep working millions on welfare depend on you ------------------- fwp@deepthought.com > > [quoted text clipped - 38 lines] >assists in providing enough PRINTING density to give a good print. > It is not true that VC paper defeats the purpose of pyro. VC paper with blue or magenta filtration makes possible very versatile use of pyro. Magenta filtration in small amounts can intensify the shadows. Pyro makes possible negatives that can have the high contrast required for printing-out papers like platinum and the normal contrast for use with VC papers. Why does Mr. Gainer say the stain adds contrast when the only reason I use it is to lower the contrast, i.e. hold highlight tones? > Why does Mr. Gainer say the stain adds contrast when the only reason I > use it is to lower the contrast, i.e. hold highlight tones? That's the wrong reason to use pyro. The better reason is to ADD density, using graded paper. You must adjust the development time downward to allow for that. You CANNOT make a pyro negative that will print ideally on both graded and VC paper. It's impossible. The amount of development that works with VC paper is rather high; the amount that works well with graded is rather lower. > It's impossible. The amount > of development that works with VC paper is rather high; the amount > that works well with graded is rather lower. Once again the HMS Nutcase. Is "Blatently Incorrect". If anything the complete opposite and even that is subject to the intended grade of paper one is making the negative for. If one is making the negative for grade two it works for either....., and even "IF" the papers are somewhat subtley different that difference is easily adjusted on the VC paper type. SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 >> It's impossible. The amount >> of development that works with VC paper is rather high; the amount [quoted text clipped - 9 lines] >either....., and even "IF" the papers are somewhat subtley different that >difference is easily adjusted on the VC paper type. Since you're responding to the nameless one, did you not also notice his embrace of a variation in development in this thread? Inconsistent?! Ahh, the hobgoblin of small minds. I myself have dabbled in inconsistentcy quite often. Then again, I do admit it. Robert Vervoordt, MFA > Since you're responding to the nameless one, did you not also notice > his embrace of a variation in development in this thread? > Inconsistent?! Ahh, the hobgoblin of small minds. I myself have > dabbled in inconsistentcy quite often. Then again, I do admit it. I was responding to the assertation,versus the nameless anything ;-) SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 >> Since you're responding to the nameless one, did you not also notice >> his embrace of a variation in development in this thread? >> Inconsistent?! Ahh, the hobgoblin of small minds. I myself have >> dabbled in inconsistentcy quite often. Then again, I do admit it. > >I was responding to the assertation,versus the nameless anything ;-) Oh, well. Never mind. TNO will be answering here with his excuses that prove that he never meant what seemed to be said, or that he said something else, or ... You get the idea. I should have ignored it, too. Robert Vervoordt, MFA > >> It's impossible. The amount > >> of development that works with VC paper is rather high; the amount [quoted text clipped - 12 lines] > Since you're responding to the nameless one, did you not also notice > his embrace of a variation in development in this thread? HUH? What I was saying was that using pyro, a different degree of development would be required to give the same result using graded paper and VC paper. That is not asvocating variable film development to adjust for scene brightness range. > Inconsistent?! Ahh, the hobgoblin of small minds. I myself have > dabbled in inconsistentcy quite often. Then again, I do admit it. > > Robert Vervoordt, MFA > > It's impossible. The amount > > of development that works with VC paper is rather high; the amount [quoted text clipped - 9 lines] > either....., and even "IF" the papers are somewhat subtley different that > difference is easily adjusted on the VC paper type. Look, dumbass: The pyro negative that prints well on grade 2 paper will NOT print well on VC paper with a #2 filter. It's IMPOSSIBLE. The difference will be in the highlights. Using a higher # filter won't work either. You CANNOT make the same negs match on VC and graded paper. > Look, dumbass: You do. As stated Blatently incorrect. SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 > > > Look, dumbass: > > You do. > > As stated Blatently incorrect. Obviously, physics and chemistry are not anything that matters to you Imbecile!. Blue-sensitive paper DOES NOT SEE GREEN! Is there something wrong with your brain, or don't you read English? Graded paper IS NOT sensitive to green! This means the stain ADDS density for graded paper. VC paper DOES see green. This means the stain passes light to which the apper is sensitive. > Imbecile!. YAWN. SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 >>Why does Mr. Gainer say the stain adds contrast when the only reason I >>use it is to lower the contrast, i.e. hold highlight tones? [quoted text clipped - 5 lines] > of development that works with VC paper is rather high; the amount > that works well with graded is rather lower. No, No, No. You did not understand my post from August 16, 2004 when you were still Michael Scarpitti. Here it is again: Michael, Please stop misleading readers. I trust you are not doing it knowingly, but the effect is just the same. Graded paper is sensitive to blue light with a very small range of sensitivity in the green spectrum. Using a pyro negative with graded paper will not affect the final image, other than, perhaps, by extending slightly exposure time, since green light has little to no affect on the graded paper. You may have noticed that one does not use yellow or magenta filters with graded paper. Does one? On the other hand, variable contrast paper is made so as to be sensitive to both blue and green light. That is why yellow and magenta filters are used. The blue light produces high contrast images. The green light produces low contrast images. Yellow filters block blue light, thus producing a low contrast image from the green light. Magenta filters block green light, thus producing a high contrast image from the blue light. Any of this sound familiar? The yellow stain on a pyro negative acts as a variable density yellow filter. In the shadow regions, the addition of the yellow stain raises the values by close to one zone, making shadows more defined. As the stain is proportionally denser in the highlights than in the shadows, the highlights are simultaneously kept from being blown out, so that more detail is observable in the highlight regions as well. There is, by the way, a couple good articles in the last two issues of View Camera that illustrate these effects of pyro. Francis A. Miniter Michael Scarpitti wrote: > "Francis A. Miniter" <miniter@attglobalZZ.net> wrote in message news:<4120e14d_2@news3.prserv.net>... >>Michael, >> [quoted text clipped - 3 lines] > No, sorry, YOU have it backwards. The stain is valued because it adds > density without grain. > >>Why does Mr. Gainer say the stain adds contrast when the only reason I > >>use it is to lower the contrast, i.e. hold highlight tones? [quoted text clipped - 21 lines] > paper. You may have noticed that one does not use yellow or > magenta filters with graded paper. Does one? The stain is seen as density by the blue-sensitive graded paper. Do you understand that or not? The stain ABSORBS blue light, just as silver does. Silver absorbs ALL colors of light, but to a blue-sensitive paper, the stain and the silver are BOTH density. > On the other hand, variable contrast paper is made so as to > be sensitive to both blue and green light. That's right, and that's why the stain is less useful: it doesn't block green light as much as silver does. It passes a lot of green light. > That is why > yellow and magenta filters are used. The blue light [quoted text clipped - 3 lines] > Magenta filters block green light, thus producing a high > contrast image from the blue light. Any of this sound familiar? Yes, but you obviously have no clue on how this relates to pyro negatives. > The yellow stain on a pyro negative acts as a variable > density yellow filter. Agreed, more or less. > In the shadow regions, the addition > of the yellow stain raises the values by close to one zone, > making shadows more defined. The stain is very minimal in the shadow regions. The stain is proportional to the silver density, so it is like an intenifier WHEN USED WITH GRADED PAPER. There is no appreciable effect in shadow areas, because there is no appreciable stain in shadow areas. > As the stain is proportionally > denser in the highlights than in the shadows, the highlights > are simultaneously kept from being blown out, so that more > detail is observable in the highlight regions as well. No. The contrast is lowered as the density is increased. Whether the highlights are 'blown out' depends on the overall amount of development. IF YOU'RE USING PYRO TO CONTROL HIGHLIGHT CONTRAST, YOU'RE USING IT FOR THE WRONG REASON. THERE ARE BETTER WAYS TO CONTROL HIGHLIGHT CONTRAST, AND PYRO BENEFITS THE USER OF GRADED PAPER MORE THAN THE USER OF VC PAPER. Is that clear? Comments interleaved. >>>>Why does Mr. Gainer say the stain adds contrast when the only reason I >>>>use it is to lower the contrast, i.e. hold highlight tones? [quoted text clipped - 24 lines] > The stain is seen as density by the blue-sensitive graded paper. Do > you understand that or not? That is one effect, but not the biggest or even a significant one. The yellow stain acts as a variable density filter, and in its role as a filter the yellow blocks the transmission of much of the blue light, its complementary color. That reduces significantly the activation of blue sensitive paper or blue sensitive elements of a VC paper. The stain ABSORBS blue light, "Blocks" is more accurate. just as > silver does. Silver absorbs ALL colors of light, but to a > blue-sensitive paper, the stain and the silver are BOTH density. See above. Density is not the biggest element. >>On the other hand, variable contrast paper is made so as to >>be sensitive to both blue and green light. > > That's right, and that's why the stain is less useful: it doesn't > block green light as much as silver does. It passes a lot of green > light. But that is what it is intended to do. That is how it reduces contrast, since the green light sensitive elements of the paper are what provide the low contrast effects in VC paper. >>That is why >>yellow and magenta filters are used. The blue light [quoted text clipped - 6 lines] > Yes, but you obviously have no clue on how this relates to pyro > negatives. I have been using PMK now regularly for about five years. Month in and month out. How much use of the process have you made. >>The yellow stain on a pyro negative acts as a variable >>density yellow filter. [quoted text clipped - 8 lines] > proportional to the silver density, so it is like an intenifier WHEN > USED WITH GRADED PAPER. Intensifying what? There is no appreciable effect in shadow > areas, because there is no appreciable stain in shadow areas. > [quoted text clipped - 4 lines] > > No. The contrast is lowered as the density is increased. That's what I said. Whether the > highlights are 'blown out' depends on the overall amount of > development. Too simplistic. If the Subject Brightness Ratio exceeds 9 zones, for instance, then the highlights may be blown out on the negative before you start. Reduced development may be one response to a high SBR, but it need not be the only one. The use of Pyro is another. If it were not for the presence of the yellow stain, certain highlights might be blown out when printed. The presence of the stain prevents that from happening. > IF YOU'RE USING PYRO TO CONTROL HIGHLIGHT CONTRAST, YOU'RE USING IT > FOR THE WRONG REASON. Perhaps, if one were always using sheet film and always individually processed each sheet, what you say might be right; but where roll film (120 or 135) is involved and individual processing is not possible, the use of pyro may help compensate for the inability to achieve individual treatment of negatives. THERE ARE BETTER WAYS TO CONTROL HIGHLIGHT > CONTRAST, AND PYRO BENEFITS THE USER OF GRADED PAPER MORE THAN THE > USER OF VC PAPER. > > Is that clear? No. Francis A. Miniter > Comments interleaved. > [quoted text clipped - 28 lines] > > That is one effect, but not the biggest or even a significant one. So, for 150 years, the people have been using pyro and blue-sensitive papers successfully are deluded? You are denser than I thought. > The yellow > stain acts as a variable density filter, and in its role as a filter the yellow > blocks the transmission of much of the blue light, its complementary color. > That reduces significantly the activation of blue sensitive paper or blue > sensitive elements of a VC paper. VC papers have three layers of similar contrast. All three are of course sensitive to blue. Blue light activates all three layers, giving the most contrast. The second layer has moderate green sensitivity in addition to blue. The third layer has considerable green sensitivity. By controlling the ratio of blue to green light, one is able to control how many layers are activated. With green light, only one layer or two is activated. > The stain ABSORBS blue light, > > "Blocks" is more accurate. Irrelevant distinction. > just as > > silver does. Silver absorbs ALL colors of light, but to a [quoted text clipped - 12 lines] > the green light sensitive elements of the paper are what provide the low > contrast effects in VC paper. That is NOT 'what it is intended to do'! Are you a complete moron, or half-moron and half imbecile? Pyro was introduced in the mid-19th century, as the first developing agent. It has NOTHING to do with VC paper, WHICH WAS NOT EVEN INVENTED FOR ANOTHER 100 YEARS! > >>That is why > >>yellow and magenta filters are used. The blue light [quoted text clipped - 24 lines] > > Intensifying what? THE SILVER DESNITY, YOU MORON! > There is no appreciable effect in shadow > > areas, because there is no appreciable stain in shadow areas. [quoted text clipped - 26 lines] > involved and individual processing is not possible, the use of pyro may help > compensate for the inability to achieve individual treatment of negatives. No, metol-type compensating developers are far superior to Pyro in sharpness, speed, contrast control, and grain. > THERE ARE BETTER WAYS TO CONTROL HIGHLIGHT > > CONTRAST, AND PYRO BENEFITS THE USER OF GRADED PAPER MORE THAN THE [quoted text clipped - 3 lines] > > No. Then learn to read English. That positively does it, anything I might have gained from your posts is totally non consequential. The complete disrespect you show people on this and other newsgroups leads me now once and for all to drop you into my killfile permanently. I am sick and tired of your crap. And I will not hesitate to inform every one new to the groups I post to do the same, no second thoughts about it troll. SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 >That positively does it, anything I might have gained from your >posts is totally non consequential. The complete disrespect [quoted text clipped - 4 lines] >every one new to the groups I post to do the same, no second thoughts >about it troll. Hurrah! I'll still watch, but I'm still thinking of making him the first to be killfiled. Robert Vervoordt, MFA > That positively does it, anything I might have gained from your > posts is totally non consequential. The complete disrespect [quoted text clipped - 4 lines] > every one new to the groups I post to do the same, no second thoughts > about it troll. I am sick and tired of people who don't understand physics or chemistry or optics making claims about photographic materials or processes that violate causation. Do whatever you want to. I don't care a whit. Then you should be pretty sick of yourself then, huh? > <The contents of the previous message have been snipped for the sake of decency> Mr. Scarpitti, you do have a foul mouth and an ill manner. Please reflect that when your family, friends and relatives come to look you up on Google in years to come they will see the untoward conduct you have exhibited to others. Is this the way you wish to be remembered? A little history is in order. In 1851, Archer et al showed that pyrogallol was effective as a developer. This was a good thing since the primary developer before that was mercury vapor (1837). But pyrogallol was, initially, very expensive and an effective practical developer using pyro was not invented until 1862, when Major Russell, author of the tannin process, combined it with ammonia (and/or ammonium bromide). Hydroquinone's developing properties (in combination with catechol) were discovered in 1880 by Abney. Metol and Amidol were invented by Andersen and Bogisch in 1891. Still with all this it was not until 1927 that D-76 was invented providing the standard by which, ever since, all developers have been measured. Remember, too, that patents would have prevented the widespread use of many of these developers for 17 years or so each after their inventions. So, yes, for a substantial period of time Pyrogallol was an important developer, not, however, because of any special effects when the negatives were printed on graded paper (for a while they were lucky to have any paper), but because it worked and not much else did. Pyro has always had the disadvantage that working solutions have a life measured in minutes. So a divided solution was the only means of keeping the product for more than one use. So when D-76 came along, Pyro was forgotten for more than a generation. What brought about the revival of Pyro was the combination of a stable formulation of PMK by Gordon Hutchings and the presence of VC paper, on which PMK could work its greatest wonders. Take away either of those - PMK formulation or VC paper - and you would not find more than a few experimenters working now with pyrogallol. As to the composition of VC papers, I am unaware of papers having three layers as you describe. Indeed, the explanation provided by Langford, Advanced Photography(4th Edition), Chapter 9, p. 159, is that the emulsion of a VC paper "is made up of a mixture of high-contrast blue-sensitive and low contrast green-sensitive silver halides." So it is the nature of the halides, not layers, that make the difference. I refer you as well to the following: http://www.wmin.ac.uk/ITRG/IS/DPI/HIW/PM1notes.pdf If you have an authoritative source of information to confirm your description of the structure of VC paper, I would be most interested to know about it - provided that you can state your position in appropriate language. Good day, sir. Francis A. Miniter Francis A. Miniter P.S. You still have not stated how long you have been using pyro as a developer yourself. > > <The contents of the previous message have been snipped for the sake of decency> Let's start here, so that you understand how VC paper actually works: http://www.ilford.com/html/us_english/pdf/Cont.pdf "All chloro-bromide (black and white) emulsions are blue sensitive with a slight sensitivity to green light. To make an emulsion sensitive to colours in addition to blue, sensitising dyes need to be added." "MULTIGRADE papers are coated with an emulsion which is a mixture of three separate emulsions. Each emulsion is a basic blue sensitive emulsion to which is added different amounts of green sensitising dye. Thus, part of the mixed emulsion is sensitive mainly to blue light, part to blue light with some sensitivity to green light and part to both blue and green light." "All parts of the emulsion have the same contrast. They also all have the same speed to blue light, but naturally, the part of the emulsion with only a small amount of green sensitising dye has a low speed (that is, is less sensitive) to green light." "When the paper is exposed to blue light, all parts of the emulsion react and contribute equally to the final image. This image is of high contrast because of the additive effect produced by three emulsions with the same speed and contrast. The resultant curve has a narrow exposure range and is thus of high contrast." "When the paper is exposed to green light, only the parts of the emulsion with the larger amounts of green sensitising dye react initially. This is because the three emulsions have very different sensitivities to green light. This image is of low contrast because of the additive effect produced by three emulsions with different speeds to green light, but with the same inherent contrast. The resultant curve has a very much wider exposure range and is thus of low contrast." "By varying the proportion of blue to green light, a contrast range between these two extremes can be obtained. The simplest way of controlling the colour of the light reaching the emulsion during exposure is by the use of filters: a magenta filter absorbs green light and transmits blue; a yellow filter absorbs blue light and transmits green. In this way, high and low contrast images can be made." > A little history is in order. In 1851, Archer et al showed that pyrogallol was > effective as a developer. This was a good thing since the primary developer [quoted text clipped - 13 lines] > graded paper (for a while they were lucky to have any paper), but because it > worked and not much else did. I have not stated that pyro has a 'special effect' with graded paper. Graded paper is blue-sensitive only. The pyro-induced stain, which absorbs blue light, acts as if it were silver density and therefore adds to the printing contrast of the image. The image in a pyro negative is formed of two components: silver and stain. Both absorb blue light. The silver absorbs all light, and the stain absorbs blue while passing green, yellow, and red. > Pyro has always had the disadvantage that working > solutions have a life measured in minutes. So a divided solution was the only > means of keeping the product for more than one use. So when D-76 came along, > Pyro was forgotten for more than a generation. Correct. > What brought about the revival of Pyro was the combination of a stable > formulation of PMK by Gordon Hutchings and the presence of VC paper, on which > PMK could work its greatest wonders. How so? The benefit of pyro is that the stain ADDS to the printing density and contrast of the silver (for graded paper) WITHOUT the drawbacks of increased silver density (higher fog, increased graininess, etc). Pyro was used long before VC paper for that reason. It does have, however, low speed potential (not counting the stain), poor sharpness, and stability problems. > Take away either of those - PMK > formulation or VC paper - and you would not find more than a few experimenters > working now with pyrogallol. > As to the composition of VC papers, I am unaware of papers having three layers > as you describe. Read the reference from Ilford above and become aware. > Indeed, the explanation provided by Langford, Advanced > Photography(4th Edition), Chapter 9, p. 159, is that the emulsion of a VC paper [quoted text clipped - 14 lines] > P.S. You still have not stated how long you have been using pyro as a developer > yourself. When used with VC paper, the green light passed by the stain affects the emulsion that is sensitized to green, producing some additional density that would not be produced if that stain were silver. It gives a weak, low-contrast image in those areas of heaviest density and contrast. The effect is that a given pyro negative cannot be made to print indetically on both graded (blue-sensitive) paper and VC paper. Because the color and density of the stain are hard to control to the same accuracy as conventional compensating developers (and because the stain effects vary from one film to another), the use of pyro as a means to control highlight density in the print is a poor approach. Different VC papers may also react differently to a given negative, so differences and changes in VC products may make it difficult or impossible to match the results on another VC paper or an 'improved' version of an existing line. If your favorite VC paper is deleted or changed, you may be unable to duplicate that favorite print. Whatever is gained by the stain is better cotrolled by conventional compensating development. An image that consists entirely of silver (or chromogenic neutral dye) can be printed on any type of paper with similar results. This is such a mess, that I have to respond, though with great reluctance being over come by a need to correctmisinformation and illogic reaching to near the level of intellectual criminality. >> > <The contents of the previous message have been snipped for the sake of decency> > [quoted text clipped - 9 lines] > >"MULTIGRADE papers are coated with an emulsion An emulsion is singular. >which is a mixture of three separate emulsions. A mixture is a combining of more than one separate emulsions into one. >Each emulsion Part of the forementioned mixture, not separate or "layers". >is a basic blue sensitive emulsion to >which is added different amounts of green >sensitising dye. Thus, part of the mixed emulsion One mixed emulsion, not several. >is >sensitive mainly to blue light, part to blue light [quoted text clipped - 9 lines] >"When the paper is exposed to blue light, all parts >of the Single, or, one. >emulsion react and contribute equally to the >final image. This image is of high contrast because [quoted text clipped - 5 lines] >"When the paper is exposed to green light, only >the parts of the Single. >emulsion with the larger amounts >of green sensitising dye react initially. This is >because the three emulsions have very different >sensitivities to green light. This image is of low >contrast because of the additive effect produced >by three emulsions Mixed into one. > with different speeds to green >light, but with the same inherent contrast. The [quoted text clipped - 5 lines] >obtained. The simplest way of controlling the >colour of the light reaching the emulsion Note the singular. >during >exposure is by the use of filters: a magenta filter [quoted text clipped - 27 lines] >blue light. The silver absorbs all light, and the stain absorbs blue >while passing green, yellow, and red. That is defined as a special effect. >> Pyro has always had the disadvantage that working >> solutions have a life measured in minutes. So a divided solution was the only [quoted text clipped - 13 lines] >It does have, however, low speed potential (not counting the stain), >poor sharpness, and stability problems. HAd, in the case of the old formulae. The PMK and other modern variants have solved or reduced the shortcomings of the ancient formulae. Sharness, speed and stability have all been improved. Ask those who have used it. >> Take away either of those - PMK >> formulation or VC paper - and you would not find more than a few experimenters [quoted text clipped - 4 lines] > >Read the reference from Ilford above and become aware. Reread it and eat Crow. Even Kodak has worked on making a single emulsion layer of mixed color emulsions for a color film. A single layer with three emulsions combined into one. >> Indeed, the explanation provided by Langford, Advanced >> Photography(4th Edition), Chapter 9, p. 159, is that the emulsion of a VC paper [quoted text clipped - 23 lines] >The effect is that a given pyro negative cannot be made to print >indetically on both graded (blue-sensitive) paper and VC paper. An enhanced choice for the artist? >Because the color and density of the stain are hard to control to the >same accuracy as conventional compensating developers (and because the >stain effects vary from one film to another), the use of pyro as a >means to control highlight density in the print is a poor approach. Or, perhaps a dazzling set of opportunities? >Different VC papers may also react differently to a given negative, so >differences and changes in VC products may make it difficult or >impossible to match the results on another VC paper or an 'improved' >version of an existing line. If your favorite VC paper is deleted or >changed, you may be unable to duplicate that favorite print. But you can still make a copy negative of that print and reproduce it, ad infinitum. >Whatever is gained by the stain is better cotrolled by conventional >compensating development. An image that consists entirely of silver >(or chromogenic neutral dye) can be printed on any type of paper with >similar results. Different papers give different results, and the discontinuance of a particular paper would have the same effect for a Silver negative as for a Silver-Pyro negative. In addition to being wrong, misquoting, disdainful and inaccurate, you are shortsighted and unimaginative in your arguments. Add illogical and repent. Robert Vervoordt, MFA > This is such a mess, that I have to respond, though with great > reluctance being over come by a need to correctmisinformation and > illogic reaching to near the level of intellectual criminality. > An emulsion is singular. > [quoted text clipped - 5 lines] > > Part of the forementioned mixture, not separate or "layers". I say we kill file the thread and move on, as well as kill filing the major "Contributer" . Those however are some valid points you bring up and I should add that in the entire time I worked doing paper testing it was never mentioned that VC BW paper was concurrently run through the Cascade Machine to obtain seperate emulsion layers, I know emulsions are not completely fixed (dry when the paper is stored, before cutting from large rolls). In a semi wet condition any layers would intermix to a degree. I suppose seprate feed lines on the Cascade machine could be set up to deposit various layers but the layers would have to be dried between coatings to eliminate intermixing. Maybe intermixing is desired but then how could one explain the paper respond seperately to different filter grades if one emulsion is over coated on another???? Since heat drying is not advantageous to faster speed VC emulsions I doubt that the layers would be set in a "recoating" operation. Never the less "I ADMIT I could be wrong. <But I doubt it :-D Rockland Colloid's Liquid Light VC, Variable Contrast Black & White Photographic Emulsion This page seems to support that a single coating can be VC http://www.adorama.com/CHLLVC16.html SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 >> This is such a mess, that I have to respond, though with great >> reluctance being over come by a need to correctmisinformation and [quoted text clipped - 12 lines] >I say we kill file the thread and move on, as well as kill filing the >major "Contributer" . "Contributor", I'm geting really critical these days. ;-/ > Those however are some valid points you bring up >and I should add that in the entire time I worked doing [quoted text clipped - 10 lines] >but then how could one explain the paper respond seperately to >different filter grades if one emulsion is over coated on another???? They found a way to make two differently sensitized emulsion batches and then mix them into one batch for coating a single layer. Kind of like baking. >Since heat drying is not advantageous to faster speed VC emulsions >I doubt that the layers would be set in a "recoating" operation. [quoted text clipped - 6 lines] > >http://www.adorama.com/CHLLVC16.html Yep. . Robert Vervoordt, MFA > > This is such a mess, that I have to respond, though with great > > reluctance being over come by a need to correctmisinformation and [quoted text clipped - 28 lines] > but then how could one explain the paper respond seperately to > different filter grades if one emulsion is over coated on another???? It doesn't bother color film, now does it? > Since heat drying is not advantageous to faster speed VC emulsions > I doubt that the layers would be set in a "recoating" operation. [quoted text clipped - 6 lines] > > http://www.adorama.com/CHLLVC16.html > > This is such a mess, that I have to respond, though with great > > reluctance being over come by a need to correctmisinformation and [quoted text clipped - 21 lines] > completely fixed (dry when the paper is stored, before cutting from > large rolls). Almost every 'emulsion' has layers within it. Look at any cross-section of a film or paper. http://www.fujifilm.com/JSP/fuji/epartners/bin/RVP100FAF3-148E_1.pdf > In a semi wet condition any layers would intermix to > a degree. I suppose seprate feed lines on the Cascade machine could [quoted text clipped - 13 lines] > > http://www.adorama.com/CHLLVC16.html > Almost every 'emulsion' has layers within it. > > Look at any cross-section of a film or paper. > > http://www.fujifilm.com/JSP/fuji/epartners/bin/RVP100FAF3-148E_1.pdf > Velvia is a color slide film, so its emulsion will have multiple layers. As will color negative film. But not B&W film or paper. B&W Paper will have a baryta layer if it is FB or a resin coated back if it is RC type. Film has an emulsion and a film base. But the emulsions themselves are not divided into layers. Francis A. Miniter > Velvia is a color slide film, so its emulsion will have multiple layers. As > will color negative film. But not B&W film,.... But the emulsions themselves are not divided into > layers. Actually in truth I know of an exception w/regard to B&W film. That is Forte 400 speed film. The literature states that it does in fact have two seperate emulsions which allows it to capture highlights independant of midtones and shadows,.... whatever that means. SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 >> Velvia is a color slide film, so its emulsion will have multiple layers. As >> will color negative film. But not B&W film,.... [quoted text clipped - 7 lines] >it to capture highlights independant of midtones and shadows,.... >whatever that means. Thanks for that, Greg, That was a trick, well a design decision, employed with Ansco Super Hypan (GAF 500) in which there were two distinctly different emulsions used to extend the range of the film from shadow to highlight with normal, averaging exposure methods. It worked pretty well to give predictable results in rangy situations. At the time, many photographers were dwelling on pushing film to its maximum and slighted the benefit of the sharp toe rise of this film, which, if respected, could give a very deep black with good middle tone contrast and recoverable highlight detail. Tri-X, with its very long toe and more pronounced shoulder lent itself to pushing, and seemed to be more in favor. I'm not sure, but Dupont made a film called SX Pan, or something like that that may have been similar to the Ansco product as its claim to fame was that there was no practical shoulder. Whether these were two layer coatings, I believe the Ansco product was, or a single, mixed coating, is really irrelevant here. The question was about papers, and that seemed to be quite clear in the case of the Ilford documentation; it is a single, mixed emulsion. Now, even that is not really relevant to the original argument about the use of Pyro staining developers. Yes, Pyro stained negatives give additional density to the highlights of blue sensitive papers. Yes, Pyro stained negatives give a variable, highlight detail enhacing effect with VC papers. Yes, this is useful and controllable. Just listen to the folks who do it all the time. But, of course, Greg, you already do that. I wish the other one with no name would do so, too and then, shut up. Robert Vervoordt, MFA > This is such a mess, that I have to respond, though with great > reluctance being over come by a need to correctmisinformation and [quoted text clipped - 23 lines] > > Part of the forementioned mixture, not separate or "layers". They can be coated togerther or separately, it makes NO significant difference . In fact, Delta 400 was originally a 'mixed' emulsion but was later changed to a layered. > >is a basic blue sensitive emulsion to > >which is added different amounts of green > >sensitising dye. Thus, part of the mixed emulsion > > One mixed emulsion, not several. SO WHAT??????? > >is > >sensitive mainly to blue light, part to blue light [quoted text clipped - 32 lines] > > Mixed into one. SO f.cking WHAT, a.shole? The point, FUCKHEAD, is that there are three COMPONENTS. You are so f.cking OBTUSE you don't get the IMPORTANT POINT! > > with different speeds to green > >light, but with the same inherent contrast. The [quoted text clipped - 7 lines] > > Note the singular. You are so f.cking stupid you should be locked away. Emulsions are complex even in the singular. > >during > >exposure is by the use of filters: a magenta filter [quoted text clipped - 29 lines] > > That is defined as a special effect. By whom? YOU? THE MORON? Tell that to the people who were using it long ago! > >> Pyro has always had the disadvantage that working > >> solutions have a life measured in minutes. So a divided solution was the only [quoted text clipped - 18 lines] > formulae. Sharness, speed and stability have all been improved. Ask > those who have used it. The limitation is there, still. > >> Take away either of those - PMK > >> formulation or VC paper - and you would not find more than a few experimenters [quoted text clipped - 7 lines] > emulsion layer of mixed color emulsions for a color film. A single > layer with three emulsions combined into one. SO f.cking WHAT?????? THREE COMPONENTS, blended or layered, it makes no difference! > >> Indeed, the explanation provided by Langford, Advanced > >> Photography(4th Edition), Chapter 9, p. 159, is that the emulsion of a VC paper [quoted text clipped - 25 lines] > > An enhanced choice for the artist? What 'artist' are you talking about, moron? > >Because the color and density of the stain are hard to control to the > >same accuracy as conventional compensating developers (and because the > >stain effects vary from one film to another), the use of pyro as a > >means to control highlight density in the print is a poor approach. > > Or, perhaps a dazzling set of opportunities? Yeah, right. > >Different VC papers may also react differently to a given negative, so > >differences and changes in VC products may make it difficult or [quoted text clipped - 4 lines] > But you can still make a copy negative of that print and reproduce it, > ad infinitum. Who wants to do that? > >Whatever is gained by the stain is better cotrolled by conventional > >compensating development. An image that consists entirely of silver [quoted text clipped - 4 lines] > particular paper would have the same effect for a Silver negative as > for a Silver-Pyro negative. No, it would not. CAN'T YOU READ? > In addition to being wrong, misquoting, disdainful and inaccurate, you > are shortsighted and unimaginative in your arguments. Add illogical > and repent. You are unbelievable...and WRONG! Stick your MFA up your a.s! That's where it belongs! > Robert Vervoordt, MFA > This is such a mess, that I have to respond, though with great > reluctance being over come by a need to correctmisinformation and > illogic reaching to near the level of intellectual criminality. If there's ANY 'intellectual criminality' it's an MFA trying to discuss chemistry or physics, which you CRIMINALLY ignorant of. Get out of this thread and shut the f.ck up! >Get out of this thread and shut the f.ck up! I see that Mr Scarpitti is in fine form this evening. > I see that Mr _ _ _ _ is in fine form this evening. Who? :-) SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 >>Get out of this thread and shut the f.ck up! > >I see that Mr Scarpitti is in fine form this evening. Yes, and I pushed him over the edge. Sorry, John, I couldn't keep quiet any longer Did I do it on purpose, and did he fall into the trap? Whatever, I think he might just have merited banishment at this juncture. Oh, we're not moderated. Guess we'll just have to put up with more of his filth and ignorance, while some others lay more traps for him. Warn the newbies! Set the ambush! The nameless one is going to hate it. . Robert Vervoordt, MFA : >>Get out of this thread and shut the f.ck up! : > : >I see that Mr Scarpitti is in fine form this evening. : Yes, and I pushed him over the edge. Sorry, John, I couldn't keep : quiet any longer Did I do it on purpose, and did he fall into the : trap? : Whatever, I think he might just have merited banishment at this : juncture. Oh, we're not moderated. Guess we'll just have to put up : with more of his filth and ignorance, while some others lay more traps : for him. When we all ignored him he all be vanished. We should all agree to do so again. SignatureKeep working millions on welfare depend on you ------------------- fwp@deepthought.com > >>Get out of this thread and shut the f.ck up! > > [quoted text clipped - 15 lines] > > Robert Vervoordt, MFA The you have spewed forth nothing but ignorance in this group. By 'earning' an MFA, you are automatically disqualified from discussing ANTHING of a technical nature. Your brain is rotten. You cannot reason from effects to causes. You are incapable of following a simple syllogism. Get the hell out of here and shut the f.ck up, MORON! This is the reason we all agreed to ignore him. If we all ignore him he'll go away. : > >>Get out of this thread and shut the f.ck up! : > > [quoted text clipped - 15 lines] : > : > Robert Vervoordt, MFA : The you have spewed forth nothing but ignorance in this group. : By 'earning' an MFA, you are automatically disqualified from : discussing ANTHING of a technical nature. : Your brain is rotten. : You cannot reason from effects to causes. : You are incapable of following a simple syllogism. : Get the hell out of here and shut the f.ck up, MORON! SignatureKeep working millions on welfare depend on you ------------------- fwp@deepthought.com > This is the reason we all agreed to ignore him. If we all ignore him he'll go > away. We also agreed not to post his responses using his name in any form, you just did that yourself. SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 : > This is the reason we all agreed to ignore him. If we all ignore him he'll go : > away. : We also agreed not to post his responses using his name in any form, you just did that : yourself. True and I was wrong. The reason I did so was as a reminder to those of us around when we first shut him out the first time of why we did it and to demonstrate to those that weren't around then why. I will now go back to keeping the promise I made then and ignore the troll. I hope that the rest of the people following this group do the same. SignatureKeep working millions on welfare depend on you ------------------- fwp@deepthought.com |
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