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  1. #71
    Mainecoonmaniac's Avatar
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    Yes you can

    Quote Originally Posted by michaelbsc View Post
    Does this men that you cannot evaluate them with a densitometer?
    I think you have to zero out the densitometer on the film base and don't take the base density into account.

  2. #72

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    For most stained negatives you need to set a color densitometer to the blue channel, or use a blue filter on a B&W densitometer. You have to think like your printing paper when measuring densities. There is less silver density in stained negatives than normal negatives, but there is also stain density. If you use a regular white light densitometer it will therefore read less density than your paper will "see" (ie the negative will print with more contrast than you expect). The printing paper sees both the silver density and the stain density as additive. This is why a properly processed Pyro negative looks relatively thin and low contrast to the eye, but will print with higher contrast. It takes some getting used to.

    The densitometer stuff can get more complicated unfortunately depending on whether you use graded or VC paper, and also depending on what kind of staining developer you use since different developers can produce different color stains. They can range from greenish brown to yellow-orange.

  3. #73
    Bob Carnie's Avatar
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    When you say will print with with more contrast than you expect.

    Do you mean the contrast filters will need to be higher to get the same contrast print as a non staining neg of same subject matter? or do you mean that a pyro neg will need a contrast filter setting lower to get the same contrast as a non staining neg of the same subject matter?


    Quote Originally Posted by Michael R 1974 View Post
    For most stained negatives you need to set a color densitometer to the blue channel, or use a blue filter on a B&W densitometer. You have to think like your printing paper when measuring densities. There is less silver density in stained negatives than normal negatives, but there is also stain density. If you use a regular white light densitometer it will therefore read less density than your paper will "see" (ie the negative will print with more contrast than you expect). The printing paper sees both the silver density and the stain density as additive. This is why a properly processed Pyro negative looks relatively thin and low contrast to the eye, but will print with higher contrast. It takes some getting used to.

    The densitometer stuff can get more complicated unfortunately depending on whether you use graded or VC paper, and also depending on what kind of staining developer you use since different developers can produce different color stains. They can range from greenish brown to yellow-orange.

  4. #74

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    Visual evaluation of negatives (silver density vs combined silver-stain density) is one thing, printing contrast (in particular, local highlight contrast) is another.

    When visually evaluating a normal pyro negative it will look thinner and lower in contrast than we might be used to seeing with a non-stained negative, because we're looking at silver density and not including the stain density in the visual assessment. Stain is proportional to the amount of silver halide reduced, meaning in highlight areas a fair amount of density when printing is coming from the stain. So what I'm saying is that if you look at the negative, the highlight areas might look comparitively thin (ie overall contrast looks low) while in printing the combined optical/spectral density of the silver and stain might be normal. So all we're talking about here is the fact with a pyro negative the density is a combination of silver and stain.

    The issue of printing contrast, what filters to use is less straight forward and really just takes experimentation. The reason is that filters increase or decrease contrast by the same amount everywhere, while stain works proportionately. That's why many people say pyro negatives are easier to print when there is delicate highlight detail to render. Vs printing a non-stained negative, the stain reduces local contrast (ie compresses tonality) increasingly as density increases, so the stain acts like a built in variable compensating contrast reduction filter. It's like having a yellow-type filter that acts more on areas of higher density than in thin shadow areas.

    The situation is further complicated by the type of paper. Typically pyro negatives will print with higher contrast on graded paper than VC paper since VC papers have a broader spectral sensitivity.

    Wait a minute... is this a test? You've got way more experience that I do! I'm suspicious.

  5. #75
    Thomas Bertilsson's Avatar
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    So, using VC papers, do you use a higher filter grade with a pyro negative than if you use a non-pyro neg of the same scene?
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  6. #76
    Bob Carnie's Avatar
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    I have the same results as you, regarding the filters or contrast needed to print pyro negs, I have found a whole grade increase starting point. Yes, maybe a bit of a test.( funny though, when I told Sandy King this , he did not seem to see the same thing, but he is using Pyrocat and has not done as much silver printing as compared to carbon printing}
    I would be interested in asking Steve Sherman this question.

    Here is a silly observation that I have regarding unstained pyro negatives.

    If you look at Richard Avedon's studio portraits of lets say the Duke and Dutches of Windsor or Marylin Monroe you will see lots of uneven backgrounds for one, but also the grain is very defined, I have always thought that his film for this time period was developed in Pyro and unstained- most likely triX.

    Super sharp, but extreme edge sharpness on these portraits on grey background.
    I am not talking about In the American West or his work on white backgrounds.

    Not sure if anyone else ever noticed this and I wonder how he made the negs.



    Quote Originally Posted by Michael R 1974 View Post
    Visual evaluation of negatives (silver density vs combined silver-stain density) is one thing, printing contrast (in particular, local highlight contrast) is another.

    When visually evaluating a normal pyro negative it will look thinner and lower in contrast than we might be used to seeing with a non-stained negative, because we're looking at silver density and not including the stain density in the visual assessment. Stain is proportional to the amount of silver halide reduced, meaning in highlight areas a fair amount of density when printing is coming from the stain. So what I'm saying is that if you look at the negative, the highlight areas might look comparitively thin (ie overall contrast looks low) while in printing the combined optical/spectral density of the silver and stain might be normal. So all we're talking about here is the fact with a pyro negative the density is a combination of silver and stain.

    The issue of printing contrast, what filters to use is less straight forward and really just takes experimentation. The reason is that filters increase or decrease contrast by the same amount everywhere, while stain works proportionately. That's why many people say pyro negatives are easier to print when there is delicate highlight detail to render. Vs printing a non-stained negative, the stain reduces local contrast (ie compresses tonality) increasingly as density increases, so the stain acts like a built in variable compensating contrast reduction filter. It's like having a yellow-type filter that acts more on areas of higher density than in thin shadow areas.

    The situation is further complicated by the type of paper. Typically pyro negatives will print with higher contrast on graded paper than VC paper since VC papers have a broader spectral sensitivity.

    Wait a minute... is this a test? You've got way more experience that I do! I'm suspicious.

  7. #77

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    Not sure there is a straight answer since the imagewise stain acts as a variable filter, reducing contrast preferrentially in the highlights vs a standard printing filter that acts uniformly.

    What I would say is that you'd typically want to give a pyro negative more development if you're planning to print on VC paper, than if you were using graded paper since the filtering effect of the stain is more pronounced with VC papers. This is why some folks advocate staying away from say small format pyro negatives with VC paper - because you need to give fuller development which counteracts the grain masking effect of the stain.

  8. #78

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    Quote Originally Posted by Bob Carnie View Post
    I have the same results as you, regarding the filters or contrast needed to print pyro negs, I have found a whole grade increase starting point. Yes, maybe a bit of a test.( funny though, when I told Sandy King this , he did not seem to see the same thing, but he is using Pyrocat and has not done as much silver printing as compared to carbon printing}
    I would be interested in asking Steve Sherman this question.

    Here is a silly observation that I have regarding unstained pyro negatives.

    If you look at Richard Avedon's studio portraits of lets say the Duke and Dutches of Windsor or Marylin Monroe you will see lots of uneven backgrounds for one, but also the grain is very defined, I have always thought that his film for this time period was developed in Pyro and unstained- most likely triX.

    Super sharp, but extreme edge sharpness on these portraits on grey background.
    I am not talking about In the American West or his work on white backgrounds.

    Not sure if anyone else ever noticed this and I wonder how he made the negs.
    Good question.

    Yes Steve Sherman would be a reliable source, particularly for Pyrocat. I have not personally used Pyrocat so I can't comment on the specifics of that particular developer. Not sure what kind of paper he uses (assuming he mostly contact prints).

    Anyhow, interesting discussion.

  9. #79
    Thomas Bertilsson's Avatar
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    Quote Originally Posted by Michael R 1974 View Post
    Not sure there is a straight answer since the imagewise stain acts as a variable filter, reducing contrast preferrentially in the highlights vs a standard printing filter that acts uniformly.

    What I would say is that you'd typically want to give a pyro negative more development if you're planning to print on VC paper, than if you were using graded paper since the filtering effect of the stain is more pronounced with VC papers. This is why some folks advocate staying away from say small format pyro negatives with VC paper - because you need to give fuller development which counteracts the grain masking effect of the stain.
    I'm beginning to wonder if there is a large difference between Pyrocat derivatives and pyrogallol based developers, grain wise. I have 16x12" silver gelatin prints on VC paper and FP4+ film, 35mm, where I have trouble seeing the grain a couple of feet from the print surface.
    But the negatives seemed to print well on Grade 2 graded paper, but I had to jump to Grade 3 for VC paper for the most part using the same negative.

    It is an interesting thread this, and I'm learning quite a bit about pyro developers. I might get some just for the heck of it to try in very large brightness range photos.
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  10. #80
    Guillaume Zuili's Avatar
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    Hi Bob,
    Given the time period most likely a mature replenished dev.
    Not sure if he processed them himself. Did he ?
    G

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