JOBO LPL 7451 color module used as a B/W module?

Discussion in 'Darkroom Equipment' started by Photonaut, Jan 6, 2013.

  1. Photonaut

    Photonaut Member

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    Hi all.

    I just bought a JOBO 7451 with a color module.

    Do you think it is possible to use this color module as a B/W module for monochrome prints?

    I would think you would need some kind of reference chart or converter chart to do it.

    It is a really nice enlarger, and I hope to be able to use it.

    Any ideas?

    Thank you.

    Erik :wink:
     
  2. Sirius Glass

    Sirius Glass Subscriber

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    I use my Jobo tanks for both black & white and color processing.
     
  3. Richard Jepsen

    Richard Jepsen Member

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    I have the MXL 670 with color head. Not sure of the differences between the 2 enlargers but you can use a color head for contrast control. My negatives are very consistent. I found it easy to just dial in magenta to increase contrast. My normal filtration is between 2 1/2 and 3 1/2, a rather narrow range. The exposure times will change slightly (under 10%). To balance exposure time between contrast grades dial in yellow with magenta in different ratios per the photo paper directions. This adds density and increases the exposure time which you may not like. Remove the red filter from the under the lens red filter assemble. Just place flat contrast filters where the red filter was.
     
  4. Sirius Glass

    Sirius Glass Subscriber

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    I use a color head for black & white printing.
     
  5. CatLABS

    CatLABS Subscriber

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    No reason not to use a color head when doing BW. If you use Multigrade paper its the easiest thing in the world. One of the super cool things about this LPL (or Jobo) color head is that it is stepless, which means there is almost no change in time when you apply the filters. Increase magenta for higher contrast, increase yellow for lower contrast, or use both to create a more fine tuning.

    Use both separately to create a split print, use the yellow to activate the low contrast layer of your variable contrast paper, then use the magenta to activate the high contrast layer, creating a larger dinamic range on the paper the would normally be possible with just a single pass.
     
  6. ic-racer

    ic-racer Member

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  7. Photonaut

    Photonaut Member

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    Thank you all for your response. Great information!

    E