How to find Durst Atlas light bulb

Hello guys,

I am helping my friends to find spare light bulbs for their Durst 138, please let me know where I can buy it or you likely to sell your spare one.

Thank you.

Alex

300W or 500W preferably.

Alex,

You just need to search a lot for these bulbs, and get lucky as you are not the only one looking for them. Three - four years ago I managed to find some after a lot of searching. I even bought a beat up L1000 just for the spare lamps that came with it.

Something else, a friend here in The Netherlands has been experimenting with Led bulbs and I know he is getting good results with his Focomat 2c. He also has the Durst 138 and I will ask him how far he got with that one . . .

Michael

There is a thread on the Large Format forum about this.
http://www.largeformatphotography.i...38S-Replacement-Bubs&highlight=durst+138+blub
The result is a G-40 bulb is an easily found replacement.
Although finding a 300 or 500w G40 might be a bit difficult.

Hi the only way I know or to get a Durst bulb is to buy a 138s that has “spare parts and bulbs with it” other than the g20 bulb, the early Durst 138s manual (this can be downloaded just search in google) you can use a projection lamp - philips 375 E 500w with a sheet of opal glass in the filter holder. Unless you are printing a lot of 5x7 negs you can use a standard size 150w photocresenta bulb up to 4x5 inch negs.

Hope your this helps a bit

Johnkpap

have you called grey supply
https://www.topbulb.com
or the bulbman
https://bulbman.com

i've had success finding random hard to find
bulbs through them ...

I know that Durst has a wonderful reputation, but the reason why they would design an enlarger around a particular bulb has always baffled me.

Don't panic

First, if you intend to enlarge negatives smaller than 4x5, you can simply use the widely available 250W opal lamps, around 10 bucks a piece

Second, if you intend to also enlarge from 4x5 and 5x7, I would recommend to look around for G120 (globe shaped, 120mm diameter, frosted) LED bulb to put in there. For use with VC paper; make sure it is in the 4000K (neutral white) range, power rating as high as possible, something around 20W should be good. For graded papers you can also use bulbs with higher color temperature (6500K). Don't use warm white bulbs (2700K), they don't produce enough light in the spectrum the paper is sensitive to. If your lamp support uses the "L" shaped bracket, switch it so the lamp is orientated in horizontal position. With condensers and lenses appropriately matched to the negative format this should give you even illumination up to 5x7. The big advantage of LED bulbs is they produce very little heat so passive cooling is adequate. The higher rated tungsten bulb that you mentioned are very difficult and expensive to find and have a very short life. Also the L138 will require an active cooling setup with the 300W+ bulbs which will create its own set of issues (noise, vibration).

"Frosted" is different from "Opalized".

Just checked - the original atlas 300 W opal bulb was sold for 400$ today at ebay. Crazy prices.
I am too looking forward to advices of adopting a LED bulb to use with L138 for 5x7 negatives..

This G40 gets you up to 150 watts, which is as high as I've been able to find.
https://www.1000bulbs.com/product/5631/SATCO-S3004.html

Here is a LED one.
https://www.amazon.com/LOHAS-20Watt...ements=p_n_feature_five_browse-bin:6104097011
The only concern is the base portion of the globe and if that will affect the illumination.

G120 is the metric version of G40, as it appears. Frosted is not the correct term, a kind of milky, translucent (not transparent) plastic. Not opal glass as the original Durst bulbs, but it works. Sorry if I caused any confusion.

ac12 said:

Here is a LED one.
https://www.amazon.com/LOHAS-20Watt-Equivalent-Decorative-Not-Dimmable/dp/B01N3XBCO3/ref=sr_1_3?s=hi&ie=UTF8&qid=1515691597&sr=1-3&refinements=p_n_feature_five_browse-bin:6104097011
The only concern is the base portion of the globe and if that will affect the illumination.

Click to expand...

No, this is a 2700K bulb and you will not get full contrast range on VC papers, as has been shown in other threads recently. The size of the base portion is of little or no concern as long as you mount it horizontally (you may have to reverse the position of the L shaped bracket in the lamp house). The LOHAS brand bulb shown above would even be okay to mount vertically.

mnemosyne said:

No, this is a 2700K bulb and you will not get full contrast range on VC papers, as has been shown in other threads recently. The size of the base portion is of little or no concern as long as you mount it horizontally (you may have to reverse the position of the L shaped bracket in the lamp house). The LOHAS brand bulb shown above would even be okay to mount vertically.

Click to expand...

Ooops. You are correct, too warm.

Another (long) thread on bulbs for the Durst 138 series: http://www.largeformatphotography.i...266-Large-format-Enlarger-Advice-Please/page4

The lowdown is that any size bulb will work if you center it properly...

Will he consider an LED conversion? I did one on a Durst 138 which is completely reversible and there are a few threads about this.Mine is below. Since then the designs, colour range and intensity of LED lights has only improved.
https://www.photrio.com/forum/threads/led-light-conversion-on-durst-laborator-138.101324/
Sure beats the expense and rarity of the old bulbs.

Why a LED conversion? A simple LED bulb works fine without changing anything in the enlarger. Just make sure it is 400K or higher, get the largest bulb you can find and center it properly. Simple, cheap and easy.

Ron789 said:

Why a LED conversion? A simple LED bulb works fine without changing anything in the enlarger. Just make sure it is 400K or higher, get the largest bulb you can find and center it properly. Simple, cheap and easy.

Click to expand...

- evenness of light direction/distribution from flat surface downlight
- higher lumens potential in downlights
- some downlights now include colour temperature variation switch. might be useful to be able to experiment with different colour temps and filters etc.
- potential to also use dimmer to change intensity for dimmer enabled downlights (may also apply to some bulbs)

Ooops, I mistyped.... I meant 4000k.
My experience with using LED bulbs in a Durst Laborator 138s, Leitz Focomat 1c and Focomat 2c:
(note: I print B&W only and cannot comment on any use for colour printing)
The light spread is equal to a traditional bulb and marginally less even compared to an Ilford Multigrade 500 system. So yes, like Tony said, there are systems that provide a more even light spread. The difference is marginal, though. One may wonder what is better: some light fall-off to the corners may be just perfect to compensate the light fall-off in the negative caused during exposure in the camera.
The LED bulbs strangely enough produce much more light, resulting in much shorter exposure times compared to traditional bulbs. I cannot explain why this is, but exposure times with an X lumen LED bulb tends to be 2 to 4 times shorter than with a (same) X lumen traditional bulb. Maybe this is due to spectral coverage differences... I don't know.
Colour temperature variation may be interesting but may also add complexity when combined with multigrade filters. I prefer not to have too many variables.
I've never tried dimmers in the darkroom but I suppose one could combine a dimmer with a LED bulb. I have such a dimmer / LED combination in my living room. I never felt a need to use in in the darkroom.

By the way, I have some very large, traditional bulbs for the L138s (or other large format enlargers): 2 Thorn 220V - 300W, 1 Atlas 220V - 200W. If anybody is interested in buying, just let me know!