Variable Contrast Masking

Discussion in 'Enlarging' started by tkerby, Jan 5, 2005.

  1. tkerby

    tkerby Member

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    As a user of both digital and traditional cameras, I had an idea recently for variable contrast printing. I think it may get some digital photographers back into the darkroom. I greatly prefer the results I achieve through traditional photography, although I use digital for snapshots for cost, and also instead of a polaroid back in the studio. The majority of my creative work is done traditionally, with some work on scanned negatives.

    This idea is similar to the some digital enlargers used in high street photography. It is a combined digital and analog process, so apologies if it is inappropriate for these forums. Please let me know if it is and I wont post such things in future.

    I've always liked split contrast printing, and dodging and burning to improve photos. In fact I often go to the trouble of cutting out a test print to create custom masks for this purpose. I think this process could be made easier through the creation of an overlay acetate to place over the paper when printing. This could consist of contrast and exposure information, and even the inverse base colour when printing a colour film. I've not tried this idea yet, but would appreciate feedback. The process is as follows

    The digital part (unless coloured pens are your thing......)
    1 - Make a test print in the darkroom (required if only a flatbed scanner is available, otherwise optional)
    2 - Scan either the print or negative to form a base image
    3 - Resize the image to desired enlargement proportions, or to match test print
    4 - If a colour negative was scanned, sample the base colour and add the inverse of this as an additive layer
    5 - Working above the base, create a layer for each contrast grade as additive layers, each should be set to the appropriate contrast colour (green through magenta). I think for dual contrast, layers could overlap
    6 - Add a final layer as a monochrome layer to dodge and burn. Set this to a midtone and add/subtract to the layer
    7 - Print the resulting image on acetate and the scanned image on paper for alignment


    Back to the darkroom :smile:
    8 - Setup the enlarger with the scanned image as reference
    9 - Place paper followed by acetate over the image
    10 - Expose as normal allowing longer exposure time due to mask



    I've used this technique before for adding my initials to prints by writing on acetate and also to add text to dark areas on postcards. Next time I'm in the darkroom, I'll have to try it on a print. I think it may prove a particularly useful technique after an effect has been planned through completely traditional printing and many similar prints are required
     
  2. wfwhitaker

    wfwhitaker Member

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    I think in principle it's a good idea. It's been addressed before by others including Alan Ross who wrote a series of four articles on masking which were published in View Camera.

    If the mask were in placed in contact with the print, however, hard edges would result. Instead it is placed just above the negative. I've not tried the computer generated masks, but have made simple masks by drawing on the acetate sheet with a pencil. It does make tedious dodging very much more manageable.
     
  3. Paul Howell

    Paul Howell Member

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    Do you use glossy or matt acetate?

    Best

    Paul
     
  4. tkerby

    tkerby Member

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    I'm thinking glossy would be best - matt might blur the actual print slightly