Bulb from enlarger reflecting off paper

Discussion in 'Darkroom Equipment' started by jbridges, Feb 22, 2010.

  1. jbridges

    jbridges Member

    Messages:
    124
    Joined:
    Dec 16, 2007
    Location:
    AR
    Shooter:
    Multi Format
    I print with a Durst CLS 501 enlarger and lately the circular shape of the bulb(Colamp 250s)(24v250w) is printing onto the paper. The bulb is like a projector bulb and it's the cone shape that is printing onto my paper. This happens if I am making a 6x6 or a 12x12.

    I'm wondering if it's the last life surge of the bulb or something more serious. I haven't had it long enough to go through a lot of bulb replacements, but long enough to know that this is a new problem.

    Any clues would be helpful. I do have a new bulb in my B&H shopping cart but wanted to hear from some pros before I buy something I can wait on.

    thanks,

    jb
     
  2. Nicholas Lindan

    Nicholas Lindan Advertiser Advertiser

    Messages:
    2,384
    Joined:
    Sep 2, 2006
    Location:
    Cleveland, O
    Shooter:
    Multi Format
    You have the condensers in the wrong position, or the wrong condensers, for the focal length of the lens.
     
  3. Ian Grant

    Ian Grant Subscriber

    Messages:
    19,242
    Joined:
    Aug 2, 2004
    Location:
    West Midland
    Shooter:
    Multi Format
    If there's condensers then it's the wrong light source, this is a diffusion head, with a light mixing box.

    Sometimes the silver reflector material on the cone deteriorates, I've had it happen with similar bulbs used for display purposes.

    Ian
     
  4. OP
    OP
    jbridges

    jbridges Member

    Messages:
    124
    Joined:
    Dec 16, 2007
    Location:
    AR
    Shooter:
    Multi Format
    I'll check the cone for deterioration and go ahead and order a new bulb, can't hurt. Thanks for the information!

    jb
     
  5. ic-racer

    ic-racer Member

    Messages:
    7,890
    Joined:
    Feb 25, 2007
    Location:
    Midwest USA
    Shooter:
    Multi Format
    Hmmm...very odd. Did one of your diffuse plates fall out when changing mixing boxes or something?
     
  6. OP
    OP
    jbridges

    jbridges Member

    Messages:
    124
    Joined:
    Dec 16, 2007
    Location:
    AR
    Shooter:
    Multi Format
    That's a good idea. I'll check tonight.