UV Sources

[alexhill]

I must say I'm kind of surprised that there isn't a sticky full of peoples UV sources, the processes they use, and approximate exposure.

I've been researching for a uv source myself for a post collage price point, and its difficult.

So far what I'm leaning towards is: facial tanning lamp (110 usd), some sort of homemade blacklight contraption (who knows usd), a grow lamp from a hydroponics store (again unsure of usd).

What are you guys using?

 

[bblhed]

The place where I work has a silk screening shop and I use there UV exposure table. The table may not be an option for you, but I will tell you that it is nice and I have gotten spoiled by having a UV table with a timer and running water in a dark room (there safe lights are yellow). Before I got up the nerve to ask the silk screen guy to use the table I was using the Sun, it was cheep and available, but exposures took longer, wind was a problem, and believe it or not the sun is not the most reliable UV source.

I looked at tanning lamps before I gained access to the table, and they looked either too expensive new, or too dangerous from an electrical standpoint used. I did give some thought to using a halogen work light but wasn't sure of the UV output, and in a fit of insanity I thought about getting a bunch of stuff ready to print and going to a tanning salon and using a tanning bed, that would have been funny.

One thing I notice with the UV table is that when I put my sandwich of paper and negatives in and apply the vacuum the whole thing looks like a mess of newton rings but the prints come out great with no signs of newton rings transferring onto them.

If your working why not see if your employer or a sub contractor of yours has a UV table you can use. Another thing you can do is see if there is a local shop that does silk screening and will do your exposures for you, or with you assisting. Some of the people that do this type of work are graphics geeks and might let you do it just so that they can see how the process is done and what the results look like.

 

[jeffreyg]

Alex
You didn't say what size bulbs you need. My light box is from Edwards Engineering through Bostick & Sullivan and I use blacklight bulbs from Light Bulbs Unlimited (a local lightbulb store). Not costly and they work fine for pt/pd. If you are so inclined you could make your own light box. It doesn't require many parts just woodworking ability.

http://www.jeffreyglasser.com/

 

[ann]

check out some old fashion contact printing boxes on ebay and switch out the light with a uv light.

 

[sly]

I actually do use a tanning bed. It was cluttering up a friend's garage - had been there for a few years ever since Granny had gone to the big beach in the sky.
I bought it for $50. I could expose a dozen or more 8x10's at a time if I had enough contact frames, but usually I do 3-5 prints at a time. It folds up against the wall when not in use.
Depending on the process (and the negatives) exposures are in the 3-10 minute range.

I don't use it for tanning.

 

[Rick A]

If you ever want to take a road trip to north central Pa., I have all the parts you need to make an 18"x24" UV exposure unit including bulbs, timers, and even a vavuum easel with motor and hose. Oh ya, its all free for the taking. I dismantled a repro camera for other parts, and I've decided I wont be needing these.

 

[Vaughn]

Check this out...

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

I use several different types of UV light. Self ballasted reflector mercury vapor lamps make for a nice portable system -- I use a 450W and a 750W bulb, but I don't see them in in the catalogs anymore, so they may be hard to find. This is the type I use for carbon printing. I use the "pizza oven" style of light (box of black-light tubes) for pt/pd.

The type of lamp and its strength can affect sharpness, contrast, and printing time.

There are also these single self-contained Blacklights -- plug in and expose -- but you would need perhaps 5 or 6 for an 8x10.

http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

But there are also other flourence bulb fixutures you can buy ready to go -- just buy the blacklight tubes. There are two types -- BL and BLB. Not much difference in UV output, but the BLB has a more expensive visible light filter built in (the BL's are white like regular tubes)

 

[Marc Leest]

I use sometimes the good old sun. And it shines for free !

 

[holmburgers]

I'm facing the same issue myself.... good timing for the thread!

I'd be interested in a method that's slow, as long as it's cheap, reliable and good. If I had to let a print sit overnight, that'd be ok with me.

What consumer lights put off the greatest UV? For instance, how long would it take to make a print on dichromated gelatin with a single blacklight??

 

[Nicholas Lindan]

A couple CFL black-lights, some scrap wood to form an overhead 'U', a baking tin painted white inside for a reflector.

 

[jon.oman]

Check out this link. It shows plans for a UV box.

http://www.thinktink.com/stack/volumes/voliii/equipment/uvlamp/uvlamp.htm

 

[Loris Medici]

If you're going to build your own UVBL lightsource, you'd better opt for "electronic" ballasts. They're more productive (higher refresh rate, less flicker, more energy output per given exposure time...) and they keep the bulbs in good shape for a longer time (thanks to complex - microprocessor controlled - start routines).

Just my 2c.
Regards,
Loris.

 

[TheFlyingCamera]

Check this out...

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

I use several different types of UV light. Self ballasted reflector mercury vapor lamps make for a nice portable system -- I use a 450W and a 750W bulb, but I don't see them in in the catalogs anymore, so they may be hard to find. This is the type I use for carbon printing. I use the "pizza oven" style of light (box of black-light tubes) for pt/pd.

The type of lamp and its strength can affect sharpness, contrast, and printing time.

There are also these single self-contained Blacklights -- plug in and expose -- but you would need perhaps 5 or 6 for an 8x10.

http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

But there are also other flourence bulb fixutures you can buy ready to go -- just buy the blacklight tubes. There are two types -- BL and BLB. Not much difference in UV output, but the BLB has a more expensive visible light filter built in (the BL's are white like regular tubes)

Vaughn-

I use six of those fixtures to expose up to 16x20. Contrary to popular belief, the tubes do not have to be a fraction of an inch apart to provide even coverage. I have them screwed to the bottom of a shelf in an IKEA adjustable shelving unit. The next shelf down is about six inches below the shelf with the bulbs attached, which puts my contact frame's glass about 1" - 1 1/2" from the bulbs. I typically get 6-7 minute exposures for pt/pd printing, and it looks like I'm in the sub 5 for gum bichromate.

 

[holmburgers]

I went to the pet store last night and they have an awesome selection of bulbs. The beauty is; they all present the UV output on the package! The Repti-Glo Desert light seemed to have the best output. I don't know and haven't yet checked how this compares to black-light bulbs or whatever, but it's something to consider.

To make the best choice, we need to know what slice of the spectrum our material is most sensitive to.

How about dichromated gelatin, what is it's peak sensitivity?

 

[removed account4]

depending on what you need ...
you can get an old contact printer and just change the bulbs
( that is what i did ) or you can get a facial tanner
and build a box for it ( that is what i did ) ...

either way it is not too expensive and it works ..

good luck !
john

 

[Hexavalent]

How about dichromated gelatin, what is it's peak sensitivity?

360-400 nm

 

[Ole]

I use sometimes the good old sun. And it shines for free !

Not around here it doesn't - at least not this time of year!

I use a growlight. A sodium one - seems to work, as long as my wife isn't using it for jumpstarting plants in the early spring...

 

[Vaughn]

Not around here it doesn't - at least not this time of year!

And here, even though we are just under half way between the equator and the North Pole, we get a lot of rain and fog -- and I do 99% of my print making after the sun sets.

Another thing about the banks of BL (or BLB) tubes -- one does not gain anything by moving the contact printing frame closer to the bulbs...6 inches away can be just as fast as 3 inches away.

 

[karl burke]

Does anyone have a PDF of the John Edwards exposure unit ? The link to it from old threads is no longer valid.
Thanks.

 

[jeffreyg]

Karl,
The link to Edwards is Dead Link Removed

http://www.jeffreyglasser.com/

 

[holmburgers]

Ian, thanks for the sensitivity on DCG!

Here are the aquarium bulbs I referred to... http://www.exo-terra.com/en/products/compact_fluorescent_bulbs.php

I wish the spectrums were bigger, maybe larger pictures are lurking somehwere.

Can anyone comment on how these compare to BLB? Any idea of approximate exposures? Worth it?

 

[R Shaffer]

Ian, thanks for the sensitivity on DCG!

Here are the aquarium bulbs I referred to... http://www.exo-terra.com/en/products/compact_fluorescent_bulbs.php

I wish the spectrums were bigger, maybe larger pictures are lurking somehwere.

Can anyone comment on how these compare to BLB? Any idea of approximate exposures? Worth it?

The best article I know of for alt process UV lamps is by Sandy King

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

My BL bulbs peak at 350nm. Looks like the bulbs you reference would work, but I have no clue as to how they may compare in exposure times.

 

[holmburgers]

Thanks Mssr. Shaffer, I'll give it a look.

I'm curious if CFL black-lights would have an application..

edit: You know, LED's are not covered by Sandy King; I wonder if someone has investigated their use in alt. printing fully. They could be an excellent choice as well.

 

[Hexavalent]

CFL black lights work just dandy - I took a few with me to the cottage as part of a travelling carbon-printing kit. (yes, it is a severe addiction)

 

[holmburgers]

Ian,

You're referring to something like this..... http://www.homedepot.com/webapp/wcs...27X-_-100653098&locStoreNum=2207&marketID=129

Right?

If so, what kind of configuration do you use them in, and how many? Do they require ballast, or are they just "plug and play"?

Also, found this for LED's -> http://www.instructables.com/id/UV-LED-Exposure-Box/