If I recall correctly you've secured the make of enlarger bulbs when Philips stopped making them.
Very fine. And I bought some.
But I know a lot of people owning and using Durst enlarger in need of a 100 mm diameter bulb in the 250 to 300 W range to power the 60's and 70's enlargers like the 138, 139 and Laborator 1000.
Do you know if a short run of these bulb could be feasible which would make life for these beast far easier ?
Many thanks in advance for your research and answer !
we still have a good stock of Philips 250 W enlarger bulbs which we bought from their last production run. They are in the webshop.
Making a different sized bulb again is very unlikely with todays market volumes.
Thank you, Mirko for your answer.
The problem does not lie in the power of the bulb ( I know of 65 mm diameter 250 W E27 bulb) but the size of the Opaline outer glass.
These enlarger have big condenser and if you want even lighting on the baseboard they require as big a bulb as possible.
Durst used 100 mm diameter bulbs when designing these beasts, and these bulbs where common then. Now they are long gone !
This is why I asked if someone can secure a bulb in the 250 ~ 300 W range but with as big a bulb as possible to go above the standard 65 mm diameter size.
So the enlarger (I'm not familiar with that model at all) is depending on the outer envelope of the bulb to act as a diffuser? All the ones I've seen have either a mixing/diffusion box or the condensers are designed to be focused at infinity wrt the bulb, i.e. they convert a point-source into parallel rays.
Anyway, you should be able to find a ~100mm white glass sphere at a lighting shop and then place a much smaller bulb inside it if that is the required effect. You may have to forcibly ventilate the air between sphere and bulb though to prevent overheating of the bulb.
George, see my PM.
Polyglot, interesting idea. Over here I still see 95mm opalescent bulb 100W E27 lamps on the shelves. One could cut off those bulbs.
Hello all !
actually it works with a smaller bulb (otherwise the Durst 138 and 139 won't sell at all ;-) ) but light is much less even on the baseboard and centering the bulb is more difficult.
These enlarger are a compromise : the bulb is staying up on a box with a square opening on it. this square opening direct the light on a 45° mirror (sitting in the front of the enlarger which explains the shape of the front face) which in turn light the double condenser system above the negative carrier. They are not straight condenser system nor diffusion enlargers but a mix between them.
In he past I used Philips Halogena 150W double envelope 220 V halogen bulbs with a large (95 mm ) bulb. But the short working time turned them with black spot soon. (the halogen system hasn't got enough time to run correctly) add to that that 150 W is not enough to get decent printing time with warm and slow papers like the Foma or the late Forte one makes me dream of a 300 W 100 mm diameter enlarger bulb !
Agx, Yes, I've seen your PM, but I searched all bulb specialist for suitable bulbs and found nothing (even NOS Philips bulbs of correct size are long gone)...
I've been told to add a stainless steel bowl at the read of the lamp to make it appear much larger, so, with the glass bulb idea I've something to play with ;-)
Thanks both for your help and advice !