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  1. #1

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    Pyro negatives - Cold light or dichro?

    Hi,
    I just bought an used DeVere 507.
    I develop mostly in pyro and print on VC paper (most times with no filter) because, according to G. Hutchings, the yellow stain allows to get very subtle tones in the highlight areas, which is what I am looking for.
    the question is, if I ever tried to adapt a cold light head to my enlarger, would its spectrum diminish the advantaes of using pyro?
    What would be in general the advantages or disavantages of using a cold light with pyro?

    Thanks
    gm

  2. #2

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    A cold light head produces a diffused light, similar to a Color head, but it has a different color spectrum. If your DeVere has a Dichro Color head, I'm not sure you would see much advantage to a Cold Light head, but if your enlarger is a Condenser head, then you will notice a big difference.

    Cold light heads originally were a somewhat less expensive diffusion light source than a Dichro color head. For B/W they both serve the same basic purpose, to produce a flat smooth light that minimizes negative dust and flaws on the print.

  3. #3
    Ian Grant's Avatar
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    I used a De Vere Cold cathode head for around 30 years, and had no problems with staining developers. I'd still still be happily using it today except I upgraded to a De Vere 5108 and Colour head.

    Now virtually all my negs are made with Pyrocat HD and I far prefer simplicity of the Dichroic head as I only use VC papers.

    Ian

  4. #4

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    I use an old De Vere with cold light but with graded papers. I have tried under the lens filters with little success on vc. Is there some type of blue light filter that is recommended for use with VC papers ? Any info welcome.
    Regards,
    John.

  5. #5
    Ian Grant's Avatar
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    John, I never had a problem with my 60's De Vere cold cathode head and VC papers with below the lens filters. However the tubes can vary, I had to fit a new one and it was much better, the output was bluer. I've never needed to push to the extremes of a VC paper virtually all my negative print easily on Gd 2 or 3 so I never tried 00 or 5 and the usually criticism of Cold cathode heads is lack of those extremes.

    Ian

  6. #6

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    I use an Aristo cold light with a V54 lamp, which has a cyanish cast.
    Last year I experimented with PMK Pyro (from Bostick and Sullivan) and Pyrocat HD and MC (Sandy King's formulae from the Formulary).
    I found that the PMK Pyro worked well with the lamp for low to normal grade filtration (above the neg in a filter drawer), the stain is on the yellow-green side. The soft tonal rendition was nice when it was desirable. The higher grade exposures, however, were too long for me, I assumed because of the neutral density produced by the blue filters against the yellow green film (and light).

    I was never happy with the results from the pyrocat testing. Too much to try to describe here, but I felt that the redder staining from the Pyrocat developers may work against the V54 cyanish light, producing longer exposures and in the end, the results were not what I was looking for.

    I may resume testing the Pyrocat developer again in the future (I kept good records), with so many APUG members, such as Ian, recommending it, but I needed to get back to doing photography, my normals being Rodinal and HC110.

  7. #7

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    Quote Originally Posted by Ian Grant View Post
    John, I never had a problem with my 60's De Vere cold cathode head and VC papers with below the lens filters. However the tubes can vary, I had to fit a new one and it was much better, the output was bluer. I've never needed to push to the extremes of a VC paper virtually all my negative print easily on Gd 2 or 3 so I never tried 00 or 5 and the usually criticism of Cold cathode heads is lack of those extremes.

    Ian
    Thanks for the reply Ian. I have an old De Vere Cathomag 302 which may date to the forties by the look of it. I have had it for about 4 years. When I bought it I had a new spare lamp with it. It is in full working order and I have never felt the need to change the lamp. It may well be the original and I am loathe to change it in view of the fact that Oddessy have quoted £240.00 for a replacement and at this price I would not want to be without a spare. The enlarger is fine with graded paper and no problem using negs developed in Pyrocat HD, which I have recently started using printing on graded paper. When I have used under the lens filters I have found that in some cases using a magenta filter lowers the contrast and have wasted a fair amount of paper in the attempts and have had to give up.
    Perhaps I could try changing the lamp for the new one just to see if there will be a difference.
    Best wishes.
    John.

  8. #8

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    Thanks for the feedback guys.
    I am actually using a Zone VI cold light head on another enlarger already, but I never got to control contrast well enough - whether with pyro or Rodinal negatives.
    I tried Joe Englander's additive set of Rosco filters suggested by Anchell on his Variable contrast printing manual:
    #3107
    #389
    #3304
    #3315
    #3313
    #3308
    #3202
    #68

    Beside the fact that #3313 and #3308 are light magenta, which doesn't really look additive, the spacing between the grades look pretty odd.

    SoI just bought a whole Rosco swatchbook and I will try with different shades of blue and green. Or maybe go to split print directly.
    Has anybody tried a better set?

    gm

  9. #9
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    Gordon Hutchings also likes pyro for the high degree of separation between light and dark tones. Perhaps this is simply another way of saying what you described or maybe it is another reason.

    This has been why I have used it. I use an Aristo 1212 cold light head on a Durst 138S converted to 8x10. I use Rollo Pyro in a Jobo, Ilford filters and Kentmere Fineprint VCFB. I have been very happy with this combination for enlarging 8x10 negatives and contact printing 7x17 for about 3, maybe 4 years.

    John Powers



 

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