Durst L1200 - 1 second illumination lag

Discussion in 'Darkroom Equipment' started by 36cm2, Nov 4, 2009.

  1. 36cm2

    36cm2 Member

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    Just getting the dryside of my new darkroom completed and I've noticed something that's annoying me. I've got a Durst L1200 connected to a Durst E500 voltage stabilizer, which is plugged into a Gralab electronic timer, which is plugged into an outlet.

    1) Is that the correct way to have the L1200 connected to a 3rd party timer? I always thought so.

    2) When using the timer to trigger an exposure, is it normal for it to take about one second for the enlarger to turn on, rev up its fan and then finally illuminate? I have two other enlargers (a Durst M70 and a Saunders L4500) and they don't have any delay. I don't recall the L1200 being different, but it's been a while since I've used it.

    3) If this is normal, then do you compensate for it by adding a second to your anticipated exposure time and any time you pause an exposure (e.g. for burning and dodging)?

    4) Am I wrong to expect that, when in use, the enlarger would stay on (i.e. fan on) and only the light would be triggered on and off by hitting the exposure button on the timer?

    Thanks in advance for your help,
    Leo
     
  2. Bob-D659

    Bob-D659 Member

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    The power supply for my Durst CLS450 colour head has a timer in and out sockets. The Gralab connects to those two points and the power supply plugs directly into the wall. No delay. Yes the fan should run after the bulb shuts down to cool it off, and the indicator lights on the head should stay lit up when the main bulb is off, unless the switch for them is off.
     
  3. resummerfield

    resummerfield Subscriber

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    I have the Durst L1200, which connects to the EST500, which connects to the timer (RH Designs), which connects to the wall outlet. I also have a delay, but it's more like a half-second delay.

    This is common in certain enlargers. The manual for my RH Designs "Stop Clock" timer specifically states "....Some stabilized enlargers, for example certain Durst and Kaiser models, exhibit a delay of approximately 0.5 seconds after power is switched on before the lamp lights........ The Stop Clock can compensate for this delay......."

    Only on very short exposures, such as test strips, would you notice any difference. If you do test strips in, say, 3-second increments, then do as Fred Picker once suggested, make you final exposure in multiples of 3-second increments.

    Or get the RH Designs "Stop Clock", which you can set to compensate for this delay.
     
  4. 36cm2

    36cm2 Member

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    Thanks to you both. Resummerfield, does it worry you that the fan starting up on every illumination will shorten its life? I just don't remember it working like that before I packed it up. I must be getting old.
     
  5. resummerfield

    resummerfield Subscriber

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    Not at all. The bulb burns so hot that the fan must come on whenever the lamp illuminates. Durst equipment is so well designed and constructed, that I doubt it will ever give you a problem.