Life duration Philips 300W Photocrescenta bulb

[karin bingel]

Could somebody please tell me how many hours are Philips Photocrescenta 300W/220 V (PF 609 E/51) are supposed to last?
I have just bought a Teufel 5x7 enlarger and there is somebody selling
such bulbs (at a very high price..)
Thanks

 

[Mike Crawford]

Hello Karin

I used to do a lot of printing with a De Vere condensor head on Process Lith paper which required very long exposures. The regular bulbs (150W??) were quite slow so would use the Photocresenta 300s instead. They certainley helped to reduce exposure times but blew far quicker than the regular bulbs. Sometimes in a matter of days where the normal ones lasted a long long time. (Exposure times were often five minutes or more.) However, I think this wattage was not recomended for this particular enlarger head going through a UK power supply! I don't know the Teufel but if the bulbs are recommended for this enlarger it hopefully has some form of voltage stabilising. If not, you may find them lasting a lot less than weaker bulbs.

 

[AgX]

Karin,

There might be another issue for you: Independent of the original lifetime (may it be 100h or 3h depending on type) as you most probably use it with a voltage higher than 220V the lifetime of the lamp will be (further) reduced significantly.
At 240V the lifetime of a standard filament lamp would only be 30% of what it is given for 220V, but yours is already overrated, which means the loss of lifetime will be even greater!

 

[testpilot]

It might not be a hot topic right now: I have about 6 unused Philips photocrescenta 300W bulbs; the one in my enlarger has been in there for about 18 years and still works! I don't use it very often but when I do (roughly once a month) it runs for several hours with exposures up to 3 min.! it must have about 250 to 300 hrs.! The reason I have googled the bulb is simple: I use one bulb in a lamp overhead my illustration desk every day for more than a year now. Unfortunately the lamp fell down and the filament broke!These opal light bulbs are very rare and thus hard to find. I have not found a supplier yet who offers 300W but they are needed for very large prints. I can always scan the negatives and print via an inkjet plotter but the quality is not as good!