D5/D6 Dichroic Head – Max Lamp On Time?

[cmichael]

I have an Omega D6 with a fan cooled dichroic head (same head as the D5). Is there a maximum time I can leave the enlarger lamp on? I try not to leave the lamp on for more than a minute or two for fear of overheating the head and/or power supply. Am I worried about nothing?

I like to play around with cropping and sometimes use an EM-10 exposure meter resulting in some lengthy times with the enlarger lamp turned on. When I did this with my other enlarger (Omega C760) the heat sink would get pretty hot and I would shut it down to cool for a few minutes. The C760 does not have a cooling fan like the D6. It would be nice to know that I have nothing to worry about on my D6. I suspect that this enlarger could easily handle continuous duty but I have erred on the side of caution since I do not want to damage my baby.

 

[Bruce Osgood]

I have a D5 and use it much the way you do; composing, cropping, EM-10 tests, etc.

I will at times of frustration just walk away from it and come back calmer. I have returned to it after walking the dog (30 minutes and more) to find it still on. The 250W bulb still blazing without a hint of degradation. The lamp house is too hot to handle but I just shut it down and keep the fan going for a while.

I don't think you need to worry excessively about the time "on".

 

[cmichael]

Thanks for the info Bruce... I knew there had to be someone on APUG that had already completed this endurance test.