UV Exposure Unit question

Could someone explain what the difference is between the UV exposure units
sold specifically for alternative photo processes (like Freestyle sells) and the UV
exposure units sold for silkscreening purposes (like you see on ebay all the time).
The silkscreen units seem to be about half the price of the "photo" ones.
I'm sure there's a reason, I just don't know what it is.
Thanks.

Fundamentally, there isn't really any difference. But as for the details...UV exposure units sold for alt-process typically have more lights, closer together. More lights + more ballasts = more costs. The extra lights help create more even illumination (to avoid "stripes" on you prints), and shorter exposure times, due to higher UV output from the additional lights. It's possible one of the screen-printing units could work very well, but it could also result in uneven exposure due to the bulb spacing. Exposure requirements for silk screens are much less exacting than for alt-prints.

The best advice would be to try the less-expensive unit if you have the opportunity (and can return or get a refund if it is unacceptable.)

Good luck--

Greg

Thanks Greg. I suspected the difference in the lamps might be the difference.

Check out Sandy King's article on UV light sources on unblinkingeye.com

http://unblinkingeye.com/Articles/Light/light.html