Contrast problem with Durst Laborator

Discussion in 'Darkroom Developing and Printing' started by John Hendry, Apr 4, 2004.

  1. John Hendry

    John Hendry Guest


    I have a problem getting hard contrasty prints with my Durst Laborator 1000.
    I have a condenser head and use Agfa multicontrast FB paper with above the
    lens filters from Ilford. In recent months I seem not to be getting the
    contrast from prints consistent with the higher paper grade filters and am
    wondering whether this might be attributable to an old tired bulb.

    The bulb in it is a rather large 4 1/2" diameter thing marked "p 3/15 Atlas
    110V - 200W". Can anyone confirm my suspicions about the bulb or offer any
    other explanation. Also I'd like to replace the bulb and wonder what
    suitable modern bulb alternatives would be suitable? Do I need something
    that diameter for even illumination (I have the full set of condensers)?

    What are my options regarding a cold light solution for this enlarger (on
    the cheap preferably)?

    Thanks in advance for any advice.
    John Hendry, Apr 4, 2004
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  2. John Hendry

    Gary Beasley Guest

    First look in your lens to be sure you don't have a fungus problem
    killing your contrast. Then be sure the filters are clean and not
    faded out. The bulb I've never heard of having an effect on the
    Gary Beasley, Apr 5, 2004
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  3. I also suggest checking the lens. Shine a flashlight through it and
    see if its hazy inside. The only other suggestion is to get a new set
    of filters. Even though the set you have looks OK to the eye it may no
    longer have the right transmission values. The eye is not very good at
    judging the actual transmission of filters.
    I've used Agfa paper with both Kodak and Ilford filters with good
    results although the contrast values vary a little between them. I
    think Agfa has their own set but I never saw any for sale.

    Richard Knoppow
    Los Angeles, CA, USA
    Richard Knoppow, Apr 5, 2004
  4. Is this the same stock of paper? Agfa MCC is known to loose contrast
    with aging faster than one might be used to.


    Stefan Kahlert, Apr 5, 2004
  5. John Hendry

    Nick Zentena Guest

    They used to be available for sale here but I get the impression that Agfa
    has stopped making them.

    Nick Zentena, Apr 5, 2004
  6. Has your mixing box yellowed with age?

    Peter De Smidt, Apr 6, 2004
  7. John Hendry

    Alexis Neel Guest

    The bulbs do loose contrast with age. The GE ph-213 version will
    loose a grade of contrast and 1 stop of speed as it gets toward the
    end of its life. Also, check for safelight fog, using the standard
    practice of giving the paper about 1/3 of the normal exposure you
    would for a specific negative. Then keep in the easel, and put an
    opaque object on it. wait 5 to 6 minutes and develop. If you see the
    area where you had the opaque thing, you have safelight fog, which
    will also, and even faster, fog when the paper is in the developer. (a
    way to make sure the test above is accurate is to develop in total
    darkness. Its easy to do.)

    Alexis Neel, Apr 6, 2004
  8. John Hendry

    John Hendry Guest

    Don't have a mixing box (don't think so anyway). Have a big bulb, a big
    clean mirror at 45 degrees, and a pair of various sized condensers before
    the neg holder. Is the enlarger missing something? ( well I know its missing
    a sheet of IR sheilding glass in the filter drawer but I haven't melted
    anything yet).
    John Hendry, Apr 9, 2004
  9. John Hendry

    John Hendry Guest

    Might be a dud batch right enough. Thanks.
    John Hendry, Apr 9, 2004
  10. John Hendry

    John Hendry Guest

    Thanks for those tips. I think I'd like to get a new bulb and a new set of
    filters and a fresh box of paper. What is the correct currently available
    bulb to get for a Durst Laborator 1000. Is that GE ph-213 a good choice?
    John Hendry, Apr 9, 2004
  11. John Hendry

    Alexis Neel Guest

    I'm not sure, you'd have to check what kind of bulb you need. The
    GE-ph213 is a regular screw in type bulbe, like for a lamp, just with
    the name and model number on the side not on te end. It has about a
    3.5 hour usage life.

    Don't Durst's use a long, narrow halogen type bulb? I know the 5x7
    one I used did.

    Alexis Neel, Apr 9, 2004
  12. John Hendry

    John Hendry Guest

    I eventually found the instructions for the thing and it doesn't list a
    specific bulb, but states an opal lamp bulb at least 3.5" in diameter is
    required for 135mm and longer lenses (that's me - or 2.5" for 105mm or
    less). PH213 seems to be 2 5/8" in diameter according to so would do for smaller
    formats, but I do a fair bit of 4x5.

    The instructions do mention halogen point source light units but with these
    you are supposed to use a surface coated reflecting mirror and coated
    versions of the condensers.
    John Hendry, Apr 10, 2004
  13. John Hendry

    lam Guest

    I eventually found the instructions for the thing and it doesn't list a
    hmm, i suspect you can get away with any cheap opal bulb of the correct
    wattage, as the L1000 is designed in such a way that the bulb stands upright
    and the label printing on the bulbs do not "seem" to affect much the light
    source... of course this is my unproven suspicion only : )

    on a side note, my used L1000 does not have a filter drawer....: (
    can you tell me where is the drawer located ?
    ( not the one missing on mine, but where is your's located : )

    lam, Apr 14, 2004
  14. John Hendry

    winddancing Guest

    "Real" bulbs for Durst are very thickly opalized as well as being quite
    squat. Thorn is the brand name in Europe. The "filter slot" might be the
    HAG filter (heat absorbing glass). The original post was about a L 1000
    wasn't it?
    winddancing, Apr 15, 2004
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