a UV enlarger?

[Cascam]

How about using flash (removing an eventual uv filter) as a lightsource for a uv-enlarger?

 

[holmburgers]

I don't think there'd be an advantage to doing that. Flashes aren't known for their high UV output, and the number of flashes would be absurdly high... probably several 100.

It would be a compact light source though..

 

[Hexavalent]

How about using flash (removing an eventual uv filter) as a lightsource for a uv-enlarger?

That's basically what is called pulsed-xenon, used in some exposure units.

 

[holmburgers]

steven, any tinkerings with this lately? Have you seen this btw? -> http://www.deadbread.com/crumbs/23c.html

I know it might seem futile enlarging with UV, but I hope you at least give it a go when you can find the time.

Has there ever been a remotely decent plastic lens made? Not a meniscus like what's used in Holga's, but some kind of "compound" plastic lens that offers passable image quality? How about the Kodak Dakon lenses? Apparently they were acyrlic and check it out... not too bad! flickr 1, 2, 3... With an aperture, a means to focus, and a flat field, it might just work.

Alternatively, the fewest elements in an uncoated enlarging lens, with the largest aperture, might have to suffice.

I was at a concert last night and they had those ever-present "robotic" lighting units. They have RGB LEDS and are totally programmable to produce any color and move all around, etc, etc... anyways, at one point they shined all the lights out at the audience with full-on red and I felt a strong dose of IR heat coming from them. So take this potentially worthless anecdote for what you will, but LEDS can be quite powerful & radiant outside the visible range. I assume the UV ones would act similarly.

 

[steven_e007]

Hi, Thanks for the link, that was fascinating. I wish I had tried LED strips - I have used discrete LEDs which have meant a lot of soldering.

I have two banks of LEDs of different frequencies wired up and ready to go. I hope to make comparative tests, but my employer has get my nose the grindstone at work - and my wife has done the same at home the last two weekends. Damned DIY (Moan grumble complain...)

I will, I WILL do some tests this weekend and report back.

 

[keithwms]

Has there ever been a remotely decent plastic lens made?

Why? There are plenty of apo process lenses out there. They work perfectly well, with ~no focus correction required. I have done UV photography using those and a 403 filter.

~~~

The main issue here is going to be how much enlargement factor you need. If you need to enlarge 35mm to 20x24, well, forget it- you'll probably ablate the neg long before you get enough dose on the emulsion. But for more reasonable enlargements i.e. 35mm to 4x5 etc, it should be doable.

 

[holmburgers]

Thats great Steven, best of luck at the grindstone!

 

[holmburgers]

Plastic Optics
During World War II Curtis Laboratories branched into the field of plastic optics. Backed by years of research, Curtis perfected manufacturing techniques to support the manufacture of photographic-quality plastic lenses for the armed forces. Curtis aerial lenses were substantially lighter than similar lenses made of glass...

from http://www.vintagephoto.tv/research_help.shtml

 

[michaelbsc]

The Kodak dakon plastic lenses were nothing to sneeze at. They weren't pro quality. But they brought high quality inexpensive lenses into consumer camera bodies that gave good results.

They were manufacturing marvels.

 

[holmburgers]

This company makes all varieties of unique plastic lenses. They have a line of acrylic aspheres that can be made with UV transmitting acrylic.

http://www.fresneltech.com/pdf/FresnelLenses.pdf

Having looked into this company in the past, I believe they have a minimum order of $100. If there was some legitimate interest, I might have a few things I could contribute to an order, to soften the blow. If not, I understand; just putting info in the right places.

 

[Mark_S]

My day job is as an engineer in the Semiconductor Industry - just thinking out loud, in the semiconductor industry we do a lot of exposing of photographic emulsions using UV, with very specialized pieces of equipment which behave quite a bit like enlargers. We also obsolete the equipment at an alarming rate, so there may be old parts available for sale from obsolete equipment. In general we reduce during the exposure, usually at about a 10:1 ratio, so you may want to flip the lens around, and image sizes tend to be small compared to what we use in the photo area, but it may be a good source of bits and pieces....

 

[jsmoove]

What about a plastic lens? I mean, a ton of crappy cameras use them. I believe it is possible to make high quality acrylic lenses as well... I wonder where you could find one for cheap?

https://www.surplusshed.com/pages/item/L10040.html

Not sure if this is of any help.