Durst Enlarger Laborator 184 Looong Exposures

[Chromeball]

Hey all,

First time poster - I'm a photography studio manager for a college in California. We have a Durst Labordor 184 Enlarger that is set up to do horizontal mural prints. We have the full suite of condenser lenses, lens boards, lenses, and some "new" 1000 watt bulbs. We pretty much have everything that you could've acquired for this enlarger and its all in good shape.

However, we have been experiencing some looooong exposure times for our mural prints. For instance, a 6x7 negative enlarged to 32" x 38" ish has been about a 10 - 15 min exposure with the lens wide open. 35mm enlarged to the same size or around 30x40 has taken around 30 - 40 minutes wide open.

I've put in a new 1000 watt bulb and have ensured that the correct condensers/lens are being used (as per a Durst manual) for each particular negative size.

Any thoughts on what might be the cause of this? And/or how to fix it?!

I've attached some pictures of our enlarger. Would super appreciate any tips/help/resources. Thank you!

[Drew Wiley]

Well, you could switch to a modern Durst colorhead instead, along with a more concentrated mirror box. And exactly what enlarging lens are you using, and at what f/stop ?
I remember old Durst CLS301 causing me an issue because it printed too fast - even the extremely slow Ciba color medium would print 30X40 inch in about 15 SECONDS, not 15 minutes.

I'd be worried about what kind of heat buildup those very long exposures are causing. Hope you have an aggressive exhaust fan ported outside the building.

You might also want to check that there's no intervening thick white opal glass in the light path.

And have you tried more than one kind of paper, preferably fresh?

[dsphotog]

Also, there are 2 positions for the reflex mirror, the lever on the left side of the mirror chamber. check that specification for the condensers in use.

[Chromeball]

Thanks for the suggestions so far - I looked today and there is no white opal glass anywhere between the bulb and the lens.

I have tried fresh Ilford Rc paper with no luck on shorter times..

And the mirror is in the Horizontal position and used accordingly with the condensers..

I did have another question - Are these enlarger supposed to run off 240v? Ours is a standard 120v plug and I'm now thinking that it was converted (the old owner said something about this..) and it's not getting enough power? could that be? I don't know that much about electricity.

[Drew Wiley]

That brings up a new set of potential complications. Is it run direct voltage or is an intervening power supply box with controls in place. Do you have the exact item number and rating of the bulb itself?

[Chromeball]

[Chromeball]

Okay so those are some pictures of our current "janky" electrical set up.. 120v plug coming from enlarger going to Lektra Timer. Timer is plugged into a switchbox which also has the blower fan so you can't turn on the enlarger without turning on the fan.. One good thing I guess? But the switchbox is powered by an extension cord coming from the other side of the room.

yeah... goddamn I know how crappy this setup looks, but to be fair we are in a temporary location as the college is building a new campus.

On other note, I see that there is a 240v plug in the ceiling that I imagine was there to power the enlarger in the past. so trying to figure out why they would have moved it off that. Thanks so much for the help Drew. I appreciate it.

[ic-racer]

If you are using these lamps, then, indeed, 220V would be required to get the marked wattage output from the lamp.

[Drew Wiley]

Most of those units shipped to the US were dual voltage. So if the original power supply has been bypassed, you want to check the fan voltage, which is likely to be 115, and keep that circuit separate from the lighting circuit if you decide to revert that part of the system back to nominal 240V. When in doubt about the wiring, a simple continuity tester will tell one how things link up; but you'll want help from someone familiar with those devices. The colors of Euro wiring don't equate to those here; so be aware of that too.

It is possible to modernize these lamp housings to take more powerful halogen bulbs, but then you need to be absolutely certain the fan and cooling system can keep up with it. You could ask Glenn Evans at glennview.com the price of a conversion, or related questions.

[Chromeball]

Thanks,

This is the bulb we are using.. a Thorn 1000W Bulb. It says 110 - 120 v on the bulb..so not sure. Man I was feeling so hopeful that the issue had been narrowed down.
I'll be sure to hit up Glenn Evans about this.


A look at the packaging