minimum amt of UV light source

[djkloss]

I bought a uv light bulb (one) from B&S thinking I could screw it in to a regular goose-neck floor lamp with a large aluminum globe (instead of spending the big bucks on a *real* UV light box) and bending it over a 5x7 contact print frame.

My question is; will this work or am I wasting my time? Is this enough light or do you really need more bulbs, even for a 4x5 or 5x7 negative. I'd like to try coating watercolor paper (the oil process used with bromoil) (Derek Watkins book)

Thanks,

Dorothy

 

[Vaughn]

I assume you bought one of these:

13 Watt Compact Fluorescent Ultraviolet Bulb 110v

It probably work just fine for 4x5 and 5x7. At worse, exposure times will be a little long...which can actually be a bit of a boon for many alt processes -- the ones that exposure creates a printing out image (that is then intensified by developing -- platinum, cyanotype, salt, etc). You'll get a print with a bit more even tonality. Not familiar with the needs of the process you mentioned.

Good luck!

 

[djkloss]

Thanks Vaughn,
The process is where you first coat watercolor paper with gelatin, then dry etc., then potassium dichromate, then dry etc., expose, then ink as in a bromoil. The difference is (according to the book) you omit the bleach/tan and instead coat the paper. I'm just learning this myself, so I don't have any experience to go on.

 

[Vaughn]

Then your exposure times probably will not be excessive since one is not trying to push UV through pigment laden gelatin.

The yellow of the dichromate may slow down the UV a little. Good luck with your exploration!

Vaughn

 

[SMBooth]

I would be mindful of stray UV light which may burn your eyes if not careful.

 

[Hexavalent]

I would be mindful of stray UV light which may burn your eyes if not careful.

Those CFL "blacklights" are quite safe. I wouldn't stare into one for hours on end though.

 

[holmburgers]

Hi Dorothy,

I have been using just 2 CFL black-lights for some attempts at carbon and also with a "clear gelatin & dichromate" process akin to your oil printing.

From about a foot away, I'm still underexposed at an hour, generally speaking. But, it does work!

I'd suggest getting two lamp sockets, and two of those Y-adapters that will split 1 socket into 2. Then you'll have 4 CFL BL's, and I suspect you'll be able to get really nice exposures in under an hour.

Chris