Quartz Lens/UV LED's for POP Projection Printing?

[John Layton]

Morning Musing...

It has been in the back of my mind forever it seems...that a barrier in using a conventional enlarger for alt process (PD/PT, Albumen, etc.) rests in the glass of a conventional enlarging lens, in that it blocks much of the UV light which is so necessary for anything approaching reasonable exposure times for alt process. In other words...even using a UV light source in a conventional enlarger for POP papers is very difficult...mostly due to the enlarging lens.

But how many folks remember that Hasselblad lens made of quartz...allowing it to pass UV light? Would such a lens, if used on an enlarger in combination with some highly tuned UV light source (LED?) make it a bit more convenient to print POP's by enlarger projection?

Wouldn't it be great if we could directly enlarge our wonderful negatives onto Alt-Process papers?

[Tin Can]

I made a 20X36" heavy glass on a bench, foam under contact printer

My 14X36" Camera is resting for a push

[Michael R]

Someone on APUG or here made a UV enlarger.

[Duolab123]

I think you would need carbon arc lights and then you would melt everything Duplicating the sun is the goal. Remembering the illustrations of ladies making POP contact prints, early Eastman Kodak, there was a arc source surrounded by contact frames facing inward like a Christmas tree.

Maybe Xray and magnetic lenses.

[Duolab123]

UV for slow chloride papers would be feasible.

[Mark Sampson]

Once, while at my former employer, I was asked to assist a different group who had an essentially similar problem. They had an Omega D-2 condenser enlarger; I found that a Dyna-Lite flash head was a close match to the Omega lamphouse. Not sure if the maintenance shop had to rig an adapter or not. So with that rigged, I attached a 2000 w/s powerpack and suggested that they have at it... set it t full power and just close your eyes when you press the button.
It *should* have worked... it was a secretive group, and I was very busy with my own work, so I never really found out. Except a couple of months later they gave back the Dyna-Lite gear, that research program having been cancelled (for reasons never mentioned).
I still think that approach would be a good one, though I doubt that I'll ever try it myself.

[Drew Wiley]

Most EL Nikkor enlarging lenses pass UV well. The problem with designing UV enlargers per se is the complication involving fire hazard, sufficient cooling, and risk to eyesight. You'd have to go to aerospace gasketing, sealants, and coatings. Not a simple undertaking. I've successfully enlarged onto slow contact printing papers like Azo using a conventional halogen colorhead; but alt UV processes are a different story.

[John Layton]

I should speak with my neighbor, Jon Cone (Cone Editions), who builds (under contract for various institutions) what are likely the most efficient LED UV light boxes on the planet. Efficient because he's using (lots and lots of) extremely narrow spectrum UV LED's, which I'm guessing could be utilized to create an enlarger light source. Lots of issues to be sure...but worth the conversations I think.

[domaz]

People have already used 100w COB LEDs to expose Carbon in a improvised enlarger. I believe he has done Cyanotype as well.

Don't burn your house down or waste energy with Carbon Arcs....

[jnantz]

look into the lens the durst enlarger that Michael Smith used to enlarger his 35mm negatives onto AZO. I don't remember the details other than he was very excited, and it was brighter than the sun.