Digital contrast masks for colour printing...? Yeah!

Discussion in 'Digital Negatives' started by halfaman, Aug 4, 2018.

  1. OP
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    halfaman

    halfaman Member
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    Sorry for the late answer, MEB.

    The contrast reduction mask is an unsharp and low contrast black and white positive put on top of the color negative. It gives more expoure to lights than to shadows, so you get an automatic burn of lights and dodge of shadows. The intensity is controlled by the contrast of the positive and the ammount of unsharpness is to produce a smooth gradient between different densities.

    Do a digital contrast reduction mask is very simple. Scan normally in color to positive, this eliminate automatically the orange mask and eliminate dust via ICE, and then convert to B/W, unsharp and reduce the contrast in the editing software of your choice. In my case I did it with Vuescan 9.6 and PS 6.0. Scan was done to 2000 dpi, conversion to B/W with "Desaturate" option, unsharpness was done with a "Gaussian Blur" effect of around 27 pixels, and the reduction of contrast by displacing the black point vertically in a "Curves" mask.
     
  2. MEB

    MEB Member

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    Thanks for replying and answering my question! I wasn't aware of this method. Certainly the mask helped for the structure of clouds in the sky and for otherwise pitch black areas in the creek.
     
  3. scheimfluger_77

    scheimfluger_77 Subscriber
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    Thanks for the info. I am still unclear about how you sandwiched the film. Did you mean back-to-back or some other configuration?
     
  4. jtk

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    If the goal is contrast or color ontrol in multiple specific defined areas, or overall, it might be good first to see how well (wonderfully) Nik software accomplishes those things without the detail losses/unsharpness that is inherent with film masks. Nik is free. If you don't like the digital solution, which would take only minutes, you could still go ahead with pin registered film masking, if that would better float one's boat.
     
  5. DREW WILEY

    DREW WILEY Member
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    Film can be even more precise as an emulsion-to-emulsion contact mask process. But if one does not own the proper
    registration equipment, it can be difficult to align relatively sharp masks (versus unsharp). The other problem is acetate
    film base, which is not dimensionally stable.
     
  6. MEB

    MEB Member

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    Nik isn't free anymore after Google sold it to DxO. The whole collection costs now $69 in the latest version with little improvement over the formerly free version.
     
  7. Mainecoonmaniac

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    It's really brilliant. I thought of doing the same thing with black and white negs where I could use magenta in area to pump up the contrast and yellow in areas where I want to lower contrast. Never got a chance to try it out. But in the old days, making contrast masks were a real pain. But if Cibachrome was still around, I'll bet your technique will be very popular for masking chromes for printing.
     
  8. REAndy

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    to the OP: just so I'm understanding correctly: In the Example given... NO "specific" area of the mask was manipulated in PS to "set the level of dogging/burning" to affect a specific area of the final print. In other words... the mask is just a "fuzzy, reduced contrast B/W reversed image of the negative itself". Ok, maybe that wasn't 100% totally clear...You didn't change the levels of the of the area of the mountain on the mask (for example)

    Awesome write up and examples. Thanks for sharing. I'm just trying to understand, so I can try it myself!
     
  9. Please explain s-l-o-w-l-y to me, how you made the digital contrast mask. Exactly what did you do in Photoshop?
     
    Last edited: Oct 18, 2018 at 1:13 PM
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