Delta Projection Print Scale

Discussion in 'Enlarging' started by dfoo, Mar 20, 2009.

  1. dfoo

    dfoo Member

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    I bought one of these, and have been using it over the past few nights. I have a Durst M601, and am printing on kentmere luster VC paper. I setup the aperture of the lens at F8, and print for 60s.

    After developing and fixing, looking at the print I select the tone that I like from the scale, and develop another sheet. What I've found, however, is that after developing the next sheet the selected tone from the scale, and the tone that I get on the print at the same location are not the same! Generally the tone looks to be be about 1 stop underexposed (ie: if I selected 16 seconds, the tone looks more like 8 seconds).

    What could be the reasons?
     
  2. dfoo

    dfoo Member

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    Nobody? My thoughts are that a) the scale is crap b) some sort of warm up time issue in the bulb? c) the timer isn't accurate. Any other ideas?
     
  3. Fred Aspen

    Fred Aspen Member

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    I use the Kodak version and it does fine. I would think the densities on the scale are okay and would be checking the timer accuracy against my watch. If that is good, remember the '1 stop' correction and continue to use the tool. The scales are great time/paper savers.

    In time you may discover what has gone awry but, with the correction, it is still usable.

    However, if you think it may be a warm up issue, try 6-10 second consecutive exposures and see if there is a difference.

    -F.
     
  4. Erik L

    Erik L Subscriber

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    You might try as Fred has suggested and use numerous short exposures that add up to 60 seconds rather than 1- 60 second exposure. Intermitancy effect or something like that if I recall correctly and my mind isn't fooling me:smile: Or you can just trust your eyes and subtract a stop if that is consistent for you.
    good luck
    erik
     
  5. ic-racer

    ic-racer Member

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    If you have an incandescent lamp, then warm up should not be an issue. The nice thing about this type of exposure aid is that you are not troubled with any intermitancy effects. You could double check the densities with a densitometer; my Kodak projection print scale is off somewhat. You are developing both for the same time, right? Otherwise, if it is off then you could do some experiments and adjust empirically and make note of the new times.
     
  6. dfoo

    dfoo Member

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    Yes, all prints are developed in dektol for 2 minutes. I don't have a densitometer, although I guess I could use my spot meter & a light source to check it.
     
  7. nworth

    nworth Subscriber

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    I've used the Kodak version for many, many years. It reliably gets the exposure into the ballpark, but I always have to make some minor adjustments. The adjustments are seldom as great as you describe, however. It may be that the plastic is absorbing UV or other light excessively with your particular setup and the Delta scale. First, try printing a variety of negatives using the scale to find the initial exposure. If the results are consistent (underexposure), you may be able to compensate and still have a useful tool. But remember, the scale only gets you in the ballpark.