a UV enlarger?

[Steve Smith]

I don't know the emulsion for the photo-resist reacts the same as alternative emulsions like cyanotypes.

I think it's similar. Some screen printing emulsion is very similar to gum bichromate too. It's not much more than potassium dichromate in PVA glue.

I have used the same UV source for both PCB photo resist and screen printing emulsions.


Steve.

[Mainecoonmaniac]

So gum arabic is like PVA glue?

[Steve Smith]

So gum arabic is like PVA glue?

I was thinking more of the potassium dichromate part rather than the rest of it. They both become insoluble in water when exposed to UV light though.


Steve.

[steven_e007]

So gum arabic is like PVA glue?

In a book I have about alternative processes in the gum bichromate section it does suggest you can use gum arabic if you want to be traditional, or PVA glue if you want cheaper and easier.

[Mainecoonmaniac]

Wow that's interesting! I've done gum printing before, but I don't think I have the courage to try PVA glue. With PVA glue, you don't have to worry about the emulsion going moldy.

[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.