Compact Floresant Bulbs in an enlarger

Discussion in 'Enlarging' started by ford prefect, Sep 25, 2008.

  1. ford prefect

    ford prefect Member

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    so this is more out of curiosoty than nesesity. i picked up and old 35mm enlarger at the goodwill for 5 bucks the other day (they asked me what it was when i paid for they thought it was some weird lamp) anyway i dont remember what brand it was and i am at work so i cant look but its one of those cheap small B&W enlargers alot like my Vivitar so i was wondering if i could find a CFL with an equivilant wattage (again off the top of my head can"t remember. i did not come well prepared for this question, but it did just come to me as i sat in my little security building for the last 12 hours with nothing to do) could i use that in an enlarger i though it would run a cooler temp and last longer. i dont know just thought maybe some one here would have thoughts.

    thanks
    allen
     
  2. Thomas Bertilsson

    Thomas Bertilsson Subscriber

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    it can work, but keep in mind that the output of the bulb changes. Upon lighting the bulb, the output will be less, and it will glow after you turn it off too.
    Your challenge:
    1. You need to warm up the lamp to get consistency.
    2. You need to use heavy diffusion because you can otherwise see the pattern of the actual bulb on the print.
    3. You need to cover up the print with opaque material after you turn the enlarger light off, and let the lamp 'burn out' so you don't get 'extra' exposure on your paper.
    I've done it. It works. But I failed to see the point of using it, and it was a pain in the rear.
    - Thomas
     
  3. Ole

    Ole Moderator Staff Member Moderator

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    I use one, in a HUGE Durst 138S, and find that it works. Even better than "traditional" incandescents.

    I combat the warm-up time by turning on the enlarger as soon as I go into the darkroom, and time my exposures with a lens cap. I don't turn it off until I'm finished for the day.
     
  4. Paul VanAudenhove

    Paul VanAudenhove Member

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    I don't see why it wouldn't work. Certainly with graded papers; but might need some work/testing to try to figure out what filtration is needed to change grades when using a multigrade paper. Both Thomas and Ole raise good points about warming up the lamp for consistency.
     
  5. JBrunner

    JBrunner Moderator Staff Member Moderator

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  6. ford prefect

    ford prefect Member

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    thank guys i actualy thought about the warm up issue while driving home from work, i had no idea there was already athread where some one tried it or i probably would not have asked but i'm new here and there are thousands of threads on this site so stumbling upon it was kinda slim but thanks for the thoughts i just figured i see what everyone else thought or if some one had tried and i guess i was right looks like several have so at least it wasnt as crazy an idea as i thought
    thanks again for the input
    allen
     
  7. ic-racer

    ic-racer Member

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    ...what he said..
     
  8. Rob Archer

    Rob Archer Member

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    I use one in an old Gnome Alpha II 6x9 enlarger. I keep it switched on (it generates hardly any heat) and expose by placing a sheet of thick black plastic over the negative carrier and removing it for the actual exposure. I like to use quite long exposure times (30 secs+) so accuracy is less of a problem.

    Rob
     
  9. PhotoJim

    PhotoJim Member

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    Bear in mind that although fluorescent lights tend to last a lot longer than incandescents during most normal use, when turned on and off frequently (e.g., when used in an enlarger) the lifespan of a fluorescent bulb is heavily attenuated (i.e. shortened). You will use less electricity, but you will get to use the bulb for a much shorter period of time than you would expect and that will mitigate much, if not all, of the savings.

    Incandescent bulbs are best in applications where the light is turned on and off often, or in short duration.
     
  10. nworth

    nworth Subscriber

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    The only way to tell is to try it. Thomas Bertilsson outlined most of the problems well. I would add that these lamps do not start instantly, but have a somewhat variable delay of up to about a quarter second. On starting, there may be a burst of higher intensity light before falling off to normal, and then the light will slowly gain in intensity until the lamp warms up and attains its steady state intensity. The color may vary a bit during warmup, and it may change slightly as the lamp ages. These are all problems seen to a greater or lesser extent with cold light heads for enlargers, which have been used successfully for many years. Note that the phosphors used in compact fluorescents do not emiit a continuous spectrum, and the balance of blue to green is probably different than with an incandescent enlarging lamp. You may have trouble with VC papers, and you will certainly have to recalibrate (at least informally) the filtration for various contrast grades.

    After installing the lamp, look at illumination projected on a white card (maybe matte board) without a negative. If you can see irregularities over the field, the lamp will probably not work well. Measurement with a light meter may help. Quarter stop differences will definitely show in the print.
    If all works well, try printing some negative you are familliar with, and compare the prints with ones made previously.
     
  11. fschifano

    fschifano Member

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    I've tried this with two small enlargers, a small Bogen enlarger (up to 6x6 negatives) and an Omega B-600. Both have condenser type lamphouses and on both the experiment failed to produce an acceptable result. The spiral pattern of the bulb is clearly visible on the baseboard with the negative carrier, containing a blank piece of film, in place. Different machines may produce different results, so you'll need to experiment for yourself. Aside from that problem, there is the ramp up and ramp down effect of these lamps. It can take a good 30 seconds or more for the lamp to reach peak output, and there is after glow once shut down. Leaving the lamp on for the entire printing session is often not practical. I've yet to see an enlarger that does not leak some light. Once the lamp warms up, it reaches maximum output quickly; but nowhere near as quickly as an incandescent lamp.