Enlarger bulb workaround

[Ole]

I've been struggling for a couple of days now with a particularly dense negative which needs a little burning too. But since my base exposure was almost three minutes, I tend to get bored when it comes to burning in two more stops on the bright bit at the bottom and so on - and that is with the aperture wide open! I'm beginning to think that my lightbulb is about at the end of its life - but finding a replacement 240V 300W bulb for a Durst L138S is not easy.

So in a flash of inspiration I decided to try something really different: I bought a 15W low-energy bulb! Screwed it in the socket, turned it on, adjusted the placement a bit, and suddenly I had a full stop more light. Then I realised that this is essentially "cold light", and removed the heat filter: Another stop!

And then I messed around with lenses a little, and ended up swapping the 150mm with a 180mm, and the 200 condenser with a 240. The result was surprising, to say the least: More even illumination, and yet another stop more light. I would have thought the illumination would decrease, since the condensors illuminate the whole 5x7" and not just the 4x5" I was printing, but there's no arguing with the EM-10?

The drawback is the long warm-up time of the low-energy lamp, but since I had exposure times in the minutes anyway I can use a lens cap to start and stop exposure. After all, the 15W "bulb" isn't going to heat the negative much in 10 minutes, compared to what the old 300W bulb did...

 

[Schlapp]

Five green stars to you Ole Knew it could be done

 

[David A. Goldfarb]

Sounds great. I see a Metrolux in your future.

 

[Nick Zentena]

A company here in Italy is running ads for bulbs that are instant on. I've seen one and it's much faster then normal bulbs. Might not be instant but good enough I think.

A 15 watt bulb out did the 300w? Must have been nothing but heat out of the big bulb.

 

[David A. Goldfarb]

We have bulbs in our apartment that are "instant on," but they still have some ramp time until they stabilize.

 

[Whiteymorange]

Sometimes, "instant" is a relative term.

 

[Nick Zentena]

The one I saw visually had no delay. Not that means much. But I figure if you're looking at 30 second exposure any delay will be a non-issue.

 

[pentaxuser]

3 mins exposure even with a 300W bulb! Sounds like those negs need the equivalent of a thermic lance or small controlled nuclear explosion. Both have great light outputs but read the safety instructions carefully!

pentaxuser

 

[BarryWilkinson]

Ole,

Maybe you could leave the bulb permanently on and fit a shutter to your enlarging lens?

Barry

 

[Dave Miller]

Ole,

Maybe you could leave the bulb permanently on and fit a shutter to your enlarging lens?

Barry

Which is the cold cathode solution?

Tungsten filament lamps convert about 95% of the electrical energy directly to heat, so don't be surprised at the higher output of the fluorescent lamp.

 

[Ole]

Yes, I have thought of mounting the enlarger lens in a shutter. Maybe I can find an old Compur #1 which only works on T?

 

[Schlapp]

When I spent a day in the darkroom with Mr Sanderson, he used a cathode tube enlarger with a piece of cardboard to shut the light off the paper and on again. Also he uses a metronome instead of a timer. Seems to work!

 

[Jerevan]

Hmmm... I was thinking about replacement bulbs last night while trying to sleep. Now seeing this, I think I'll have to try this out when I get a darkroom again. Just the other day, I saw someone somewhere selling older "enlarger shutters". They looked very much like the Packard shutters.

 

[juan]

Somewhere there is a thread on BLB bulbs in which Sandy King mentions measuring the consistency of the light output. He found a good bit of variation over the initial period of time the bulb was on (first minute IIRC). And after that, it varied some but much less. At the time the consideration was for alt process and the conclusion was that the variation after the first minute was not enough to be concerned about with the long exposures.

In this instance, I wonder if the instant on bulbs have the same kind of light output variation, and I wonder how well the output is stabilized. Someone with the proper measuring apparatus will have to check, I guess.
juan

 

[Ole]

There's quite a bit of variation over the first minute or so with the bulb I'm using, but since it generates very little heat I turn it on while I get ready to print, and leave it on through the whole session. Fortunately I have a lens cap.

 

[JLP]

Thanks for the tip Ole, will have to do some experimenting with my 138 now.


jan

 

[lajolla]

If the 300W Opal lamp base for the L138 is the same lamp base thread as the 150W Opal lamp for the Durst M805 and L1200, those 150W Opal lamp replacements are still available in both 230V and 115V versions at the durst on-line shop for about eight euros? Good luck.
Dead Link Removed

 

[Robbedoes]

@Ole,

Some years later...
Do you still use this kind of bulbs in your 138, and if so, have you modified the setup since then?
I’m asking this because I have the same problems getting 200 watt opals.

Best regards,
Rob

 

[Smudger]

No intention to hi-jack this thread,but down here at The Bottom Of The World,the local auction site (No-not Eb*y) is chocka (means 'Full Of ') of LED lighting heads - they vary in area - from 2x3inches up to 5x7in, claim a variety of color temps,but around 5500 K, some are dimmable, they come with diffusing panels,etc, but are basically an array of leds from sub 100 to several hundreds.
Seems to me they would make admirable light sources for enlargers..
And the cost is not frightening - NZ$ 70- 150 ( add about 20% for US$).
If the bulb in my Kindermann 4x5 enlarger ever 'Pops its Clogs' (dies),I will be giving them a good hard look.

 

[SMBooth]

No intention to hi-jack this thread,but down here at The Bottom Of The World,the local auction site (No-not Eb*y) is chocka (means 'Full Of ') of LED lighting heads - they vary in area - from 2x3inches up to 5x7in, claim a variety of color temps,but around 5500 K, some are dimmable, they come with diffusing panels,etc, but are basically an array of leds from sub 100 to several hundreds.
Seems to me they would make admirable light sources for enlargers..
And the cost is not frightening - NZ$ 70- 150 ( add about 20% for US$).
If the bulb in my Kindermann 4x5 enlarger ever 'Pops its Clogs' (dies),I will be giving them a good hard look.

Link?

 

[eclarke]

Yes, please, a link...EC

 

[Smudger]

LED lights..

OK folks,
go to http://www.trademe.co.nz/
Select 'Electronics & Photography' - 'Camera Accessories" - 'Flashes & Lighting' :
Enter ' led lights' in the Search box...89 listings to choose from at last count.
NOTE : trademe does not accept bids from buyers not resident in either Australia or New Zealand.*
It is also worth noting that any of these lights using mains power will be designed for 240 volt AC supply.
*I would be prepared to assist bona fide APUG members - please email me directly.

 

[Robbedoes]

These leds do cost much more than a ‘normal’ low energy bulb.
Large diameter bulbs can be found at Bailey

 

[Smudger]

Yes, but a CFL bulb, if that's what you are suggesting,is hardly a replacement for the new technology of LED's.
Instant on, thousands of hours of reliable output, constant color temperature,or variable,in some models,dimmable output,almost zero heat output,lightweight construction..
Makes a CFL look like a Tallow Candle by comparison.

 

[Smudger]

And the NZ dollar is running about 82 cents vs the US$,so make that Minus 20%.