UV exposure unit n’ stuff

More test prints 😀 I just recently brought a black light blue compact fluorescent  bulb – one of the 26w spiral type, I was hoping that it’d be adequate to expose up to 8×10″ prints – thus far I can comment that it does 5×7″+ (with painted overlaps) gum bichromate prints perfectly adequately and seems to expose evenly.

As you can see my exposure unit isn’t the most technical unit ever made, it’s a cardboard box and sticky tape, but it seems to work, so it’ll do for now. I was intending to use a clamp on bedside lamp, but funnily enough the lamp died when I tried the bulb (a $5 lamp housing dying to save a $30 bulb is unheard of in my experience). The box is the box the bulb arrived in 😀

I was getting 20 minute exposures to begin with, but then I cut some off the bottom and now it’s 15 min (the lamp is now 5″ away from the glass). This seems to hold true for gum and with oil prints both with %5 Potassium dichromate.

That’s a single layer in paynes grey, I’ll give it another 3 coats using cymk sep negs with paynes grey, just to see what it looks like – I have a bunch in progress atm, when I’ve done them I’ll look at making up some newer lith negs – the negs I’m using atm are all circa 2008.

I had someone steal 3×100 packs of half plate brovira from my mail box last week, one of the packs they opened and threw all of the photo paper on the ground, so I picked up about 60 sheets on the grounds that they must be good for something – I fixed a couple, and applied dichromate to them in order to see if i could get an oil print from them, and it seems to work. This is after exposure, but before inking;

Neg from a tin can pinhole camera.

And starting to ink (different neg) using a couple of makeup brushes.

And an inked photo – I learned quite a lot from this even if the result doesn’t wildly excite me – it turns out that it’s viable at least. Reasonably easy to get this much of a result too, makes me feel that I may well be able to get something interesting happening with a bit of application.

Oh, and another from a really weak blurry neg I made in a modified polaroid square shooter a few years back (the experiment wasn’t that massive a success).

Kinda pictoralist, that’s 6cm square velox.

So all in all it seems that the compact fluro ‘party lights’ actually work surprisingly well for this application, a sub $100 exposure unit is quite doable, mine was sub $30 courtesy of a lucky auction win and a ‘recycled lamp cord.

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3 thoughts on “UV exposure unit n’ stuff

  1. Greetings,I was browsing about some photo related sites and wandered in here. I just have to say, I hope whoever stole your film and dumped part of it on the ground gets ball cancer. That’s just awful.

  2. Hi, I just started doing my own home gum prints with a 60 watt uv bulb and I am wondering about how long have you been leaving your prints under the bulb before you see an image? I have been leaving mine under the light for about 3 minutes and I only get staining, not even the hint of an image.

    1. From memory with this system it vatied, but the shortest was about 12 minutes, you should do a step wedge test, so you set up with most of the print covered by something opaque, and then give an exposure, then uncover a little more, expose, and so on.

      That way you wind up with a print where it has been exposed for 1min, 2min… etc. The idea is to have a whole range of exposures ranging from under-exposed through to over exposed so that you can see what the correct exposure is.

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