Build a cold light head?

[dsphotog]

I bought a 11x14 cold light head on evilbay, it arrived with a broken tube. I got a refund & was told I could keep the housing, transformer etc.
So now I'm thinking about refitting it using off the shelf fluorescent fixtures.
The 8X10 Beseler head seems to use household grade stuff.
Any ideas?
Thanks.

[DanK]

I'd suggest talking to a local sign company....many do their own neon, and if you had the original (broken) tube, they'd most likely be able duplicate it to your specs....

Thanks,
Dan

[Eric Woodbury]

The power supply, transformer, for off the shelf fluorescent and neon is different than a cold cathode light (coldlight). The housing would work, but not the power supply. Talk to a neon sign maker about it, but when I did in this town, he didn't know anything about coldlight. The tubing and gas mixture is different than neon. If you find a good coldlight maker, let us all know. With Aristo gone or on hold, we are all worried about replacements.

If you can wait, I'm optimistic that Aristo (or whatever the company that took them over) will again make tubes. A V54 tube is a wonderful thing.

[dsphotog]

I have Aristo heads on 4x5 & 5x7 enlargers, & enjoy them both, hence the desire for a similar setup for 8x10 or 11x14.
It would be great if Aristo would produce replacement parts.
I also thought about neon, but I'm concerned about the start up time..... Maybe leave it lit and control exposure with a Packard shutter?

[Curt]

You know, I get sick every time I hear the word Aristo, it used be associated with something wonderful and positive but now just a dead future and sadness.

OK, rant aside.

I wish someone would contact a company in CHINA that would be able and willing to make cold light heads for the tens of thousands of enlargers out there and replacement bulbs or the tens of thousands of heads out there. It seems that in America the industrial spirit is over.

Or maybe simplify it with a few head and adapters for the multitude of enlargers out there. But there is always a hot bulb diffusion head. Ansel Adams original or a Color head copy.

...and I'm sorry that you got a broken bulb in your purchase, it's bad enough that they are rare but to have one broken is just sad as hell...

[nolindan]

You know, there is something funny going on...

There are diffuse cold-light sources all over the place - they are behind every LCD display. LCD's aren't all that bright, but that's because there aren't all that many cold-light tubes - the light is distributed across the back of the screen by light pipes. Put enough tubes in and the thing should be bright enough.

It should be possible to make a cold light head for not much money at all. Warm-up would be the usual problem it always is with cold lights.

Another idea would be to modify a computer display LCD so it is much brighter and use the display as the cold-light panel. Send graphics to the display for dodging and burning. There were enlarger that used CRTs for light sources for just this purpose - the enlargers were mainly used for printing aerial survey negatives.

I don't know if the blue from an LCD display is blue enough for VC paper, but that's another possibility.

Ah well, lots of ideas, little time.

[dsphotog]

When I picked up the box, I heard the sound of broken glass inside... I almost barfed!
Already knowing that a replacement is unobtainium.

[Eric Woodbury]

There are plenty of cold cathode lamp producers in the US. Here's one.

http://www.cathodelightingsystems.com/products/

However, I went to the Aristo factory once about 20 years ago, and there is more to it than meets the eye. Allen Johnson explained the phosphors, the bending, the density of the tubing, and getting the color just right. I'm sure someone can make a coldlight tube, but what would it cost? And how good would the color be? We should do our best to get the company that owns Aristo to fire up a small line of tube making.

I don't expect I'll ever need another tube, but if I were to break this one by some unfortunate accident, I would need one now and I don't know what I'd do.

PS: Morley Baer used a Mervap coldlight and I see that there is still a phone listing for that company in Los Angeles. Anybody have any recent experience with these lights?

[Henry Ambrose]

The future for enlarging light sources (such as it is) is LEDs.

Do a search here for LED heads and also look at this -- http://huws.org.uk/

[Eric Woodbury]

Henry, you may be right as there are new, more efficient, more powerful LEDs available every day. To date, however, the deep blue and UV LEDs have been limited and these are needed to be able to get high contrasts from multigrade paper. LEDs are very attractive, but cold cathode light is very efficient and makes a wonderful, even lightsource. It is hard to believe at this point in wet-darkroom photography that there will be much development in any new lightsources. Perhaps this is a case of 'better is the enemy of good enough'.