RA4 Colour Printing & Contrast....

Discussion in 'Color: Film, Paper, and Chemistry' started by Matt5791, Feb 3, 2009.

  1. Matt5791

    Matt5791 Member

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    Are there any tricks for adjusting contrast with RA4 Colour printing? - I guess the obvous one is paper type, but the available range of papers seems to have reduced.

    I have been using Kodak Supra Endura and Fuji Crystal Archive.

    Thanks for any tips,

    Matt
     
  2. Tom Kershaw

    Tom Kershaw Subscriber

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    Although I've not attempted the technique yet, masking for contrast control is often discussed. See Ctein's book 'Post Exposure' - second recommendation in one day.

    Tom.
     
  3. Thomas Wilson

    Thomas Wilson Member

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    Matt, once the film has been exposed and processed, what you see is what you get. Contrast is generally controlled on the film side of the equation. Your choice of emulsions, exposure, and processing will dictate your contrast. If you have not already, try the Fuji Pro 160 C or the Kodak Portra 160 VC. You may also find that a 1 stop push will add a little snap to your prints.
     
  4. Photo Engineer

    Photo Engineer Subscriber

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    You can lower contrast by adding Sodium Sulfite to the developer, but Dmax will start to go gray on you if you use too much. You can up the contrast by adding 3% hydrogen peroxide to the developer or 5 g/l Cobalt Hexammine Chloride to it, but the developer then beomes one-shot and has a lifetime after addition of about 1 hour.

    You can also up contrast by fixing, then bleaching in a rehalogenating bleach, washing and then redeveloping in the light. You can do this over and over until you get the contrast you want.

    PE
     
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    Matt5791

    Matt5791 Member

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    Thanks for all the advice here - very helpful,

    Matt
     
  6. Ed Sukach

    Ed Sukach Member

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    Contrast can be reduced effectively with a *very* useful tool - "preflashing".

    Done essentially the same way as it is with black and white printing, whith special attention to color balance:

    1. The final image is analyzed and balanced in the enlarger. Color correction and time for exposure is recorded.

    2. The image of a gray card covering an entire sheet of paper is analyzed and balanced. Exposure time is reduced to 10% - 20% of the exposure of the final print, and the paper preflashed,

    3 The paper then receives the final exposure - the remaining 80% - 90% of the initial analysis.

    I hope I am not confusing you with this abbreviated description. Easier to do than to write about.

    I first used this as a matter of survival - printing negatives containing images of girls in white evening gowns in direct July sunlight at noon on the front steps of a College building in Vermont. Read: *BRIGHT* sunlight.
    Originally the white gowns were blown out - big time, and the shadows were completely featureless - all corrected - saved, nearly miraculously, with preflashing.
     
  7. Mick Fagan

    Mick Fagan Subscriber

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    Matt, I'll vouch for photo engineers suggestion regarding fixing, bleaching, washing then re-developing to add contrast and saturation.

    If you go to my gallery you will see a print that is half B&W and half colour.

    I've used this technique a fair few times in the past to bump colour and saturation, very effective.

    Pre-flashing as suggested by Ed also works, but you do require strict controls on the amount of light hitting the paper.

    Neither technique for more or less colour/saturation is perfect, but they can be of help when you really need it.

    Mick.
     
  8. L Gebhardt

    L Gebhardt Subscriber

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    Masking has worked well for me.
     
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    Matt5791

    Matt5791 Member

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    So to be clear here - if I wanted to increase contrast I would develop in normal colour Dev., fix in...B&W fix? (as per Mick's idea) then bleach in a rehalogenating bleach (not sure where to find this) and then re-develop in the light, presumably in a tray?

    Many thanks for all the help.

    Matt
     
  10. Photo Engineer

    Photo Engineer Subscriber

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    Cycle is Develop, fix, wash, rehal, wash, lights, develop, wash and do whatever you want here ... blix, wash dry and end, or go back through the rehal and etc. sequence again to keep going up in contrast.

    The best fix would be C41 fix diluted as normal and then diluted for use 1:1 for this use here.

    Rehal bleach = 25 g/l Potassium Ferricyanide and 25 g/l Potassium Bromide.

    PE
     
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    Matt5791

    Matt5791 Member

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    Thanks very much for that PE.