grofofan
First of all, I’d like to introduce myself, as I’m new to this forum. My name is Günter and I’ve been involved in large-format photography for years. I enlarge my negatives using a Durst 187, but I’m having trouble sourcing opal bulbs, as this machine doesn’t run on standard opal lamps but requires large opal bulbs. The bulb diameter is approx. 120 mm. Now for my question, which Mirko might be able to answer: I recently read in the FOTOIMPEX catalogue that the lamps offered there are handmade in Germany. Would it therefore be possible to manufacture suitable lamps for the Durst machines mentioned above? The price for these can certainly be higher, as these bulbs are otherwise no longer available and are sold second-hand at exorbitant prices. This would make all Durst 138 and 187 users very happy, as they would then no longer have to worry about restocking. Best regards, Günter.
cfb_de
Hello Günter,
You should be able to have these pear-shaped moulds made by Dr Fischer: http://www.dr-fischer-gmbh.de/index.php?lang=&Bereich=2&DBereich=21
Best regards,
Franz
grofofan
Thanks for the information. I rang them up as well, and they told me that they do supply such items, but not in quantities of less than 200–300 units, which is too many for me as a private customer. It might be worth FOTOIMPEX considering adding these bulbs to their range, as there are a great many devices of this type on the market and everyone I know is looking for bulbs for their devices. I would be happy to provide technical specifications and, if required, details of a specific model or dimensions.
chrisais
Hello Günter,
I don’t actually have a source for the large opal bulbs. However, I’ve modified my Laborator 138 slightly. I’m using a clear high-voltage halogen bulb (140W) in a conventional bulb shape. I’ve inserted a diffuser plate into the filter drawer. (In my case, it’s a silica gel glass plate of the sort used for thin-layer chromatography.) I then fashioned a reflector inside using thick aluminium foil. This works very well, producing very uniform light. To focus, I can pull out the filter drawer and get a very bright image (admittedly only in the centre — depending on the magnification).
Contrast conversion filters also fit in without any problems and are somewhat protected from the heat. Simply cut them slightly larger than the glass plate and clamp them in place with a slight curve.
Incidentally, according to Osram, the switch-on behaviour of high-voltage halogen bulbs and conventional incandescent bulbs is said to be no different. So there is no risk to the timer.
Another idea would be to take a faulty bulb, cut off the bottom, and then insert a rod-shaped halogen bulb. (Osram HALOLUX CERAM ECO or Philips EcoClassic30 T32) It’s probably best to leave the cutting to a glassblower.
Regards,
Chris
[ATTACHMENT NOT FOUND]
[ATTACHMENT NOT FOUND]
[ATTACHMENT NOT FOUND]
AchimBauer
Hi Günther, I’m brand new here too; I joined this forum because I’ve got a problem similar to yours.
Chris’s solution seemed promising to me, but it won’t work for me due to a lack of space.
But as I was exploring the idea further, I made a discovery that might help you. Conrad Electronic sells DIY light bulbs. They have an E14 or E27 base at the bottom, into which you insert a halogen bulb, and a glass dome is screwed on top. They have some in alabaster with a 10 cm diameter. If that’s still too small, then cut off the old lamp and connect it to the thread of another glass. With high-strength threadlocker or a boiler sealant, that should be heat-resistant. Or have a further look on the manufacturer’s website to see if there are any larger glasses available.
Regards, Achim
grofofan
Hi everyone, first of all, thanks for the great ideas. I like the ones involving the E27 thread adapter and halogen bulbs with the filaments cut off best; I’ll give them a go and let you know how it goes soon. Sorry for taking so long to reply, but I’ve been in hospital for a while. Best wishes, Günter
