Best UV Light Source (LED vs Fluro vs HID etc)

Thank you Matt, thats encouraging. I think I may need to give cyanotype a try too, got most of the chemicals already.

Ive been prepping the light box for the new leds. Dropped the level of the shelf three inches, while doing that corrected several points that were out of square and out of level. Closed one open side in and built a drop down door for the front, still have enough openings for heat to convect out. Lit area is going to be about 24 inches square.

Digging this thread up again ...

I am looking for a replacement of my face tanner that I use for alt processes - I think the tubes are as old as the unit (bought secondhand). I am getting 15-20 minutes exposures with New cyanotype, putting the light at 15 cm away from the frame. I have been looking at DIY, but I am unsure whether I am able to put it together. And the costs of heatsinks, LEDs, tools etc will probably add up.

What about a silkscreen burner (400w, HID lamp I suppose) - do these work? I guess they run pretty hot.

The Barrina blacklight led bars the fgorga recommended work great and are easy to install. Clips come with it to hang the bars and come with 120v plugin wiring as well as jumpers to connect one to the other.

Jerevan said:

Digging this thread up again ...

I am looking for a replacement of my face tanner that I use for alt processes - I think the tubes are as old as the unit (bought secondhand). I am getting 15-20 minutes exposures with New cyanotype, putting the light at 15 cm away from the frame. I have been looking at DIY, but I am unsure whether I am able to put it together. And the costs of heatsinks, LEDs, tools etc will probably add up.

What about a silkscreen burner (400w, HID lamp I suppose) - do these work? I guess they run pretty hot.

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Those silkscreen burners are the brightest you're going to easily find. They work really well. However, they come with one major drawback. The UV light from them is not consistent. As they warm up, they produce more UV light. As they age, they produce less. So it's really hard to get a consistent exposure with those without some kind of UV sensor out in front of them to measure the amount of UV light given. Most T-Shirt factories with HID lamps don't set a time to burn the screens. They set the exposure rating on the sensor, and the sensor cuts off the lamp automatically when the desired amount of UV light is reached. So to get that set up properly would probably be your most expensive route.

You might be able to find some replacement bulbs for your face tanner. They're hard to find exact replacements for, but often times you can find new bulbs that will fit and work with different model numbers. You just have to make sure to get the size right and the UV bandwidth. It can be a bit of pain to locate them, but they're not impossible to find. Many are now sold under UV curing lights or other industrial uses rather than tanning. Though, they might be kind of expensive.

glbeas said:

https://barrina-led.com/products/ba...f-switch4-pack?_pos=2&_psq=black&_ss=e&_v=1.0

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Soldering, heatsink, etc. are all too much for me. I'd rather spend my time on photography.

The UV LED bars bought and recommended to Gary (see link above) are about as simple as it gets.

One bar gets a wire with a plug to the wall socket, the other bars get linked to that one with short linking cables which are supplied in the box. Clips to attach the bars to the surface of your box are also supplied.

It took me less than a half hour to remove the fluorescent fixtures from my homemade exposure unit and replace them with the LED bars. If you need to make a box, the woodworking will take way more time than installing the lights.

I have mine plugged into an old enlarged timer.

It all just works.

The silkscreen burner costs about as much as a new batch of replacement bulbs for the face tanner, but I will keep these two options in mind, while researching the LEDs. I can only find strips (5050 and 2835) but I suppose they work too. Buying from the US is going to be a bit fiddly and costly.

My needs are modest, doing 4x5 now and 5x7 onwards, and given the limited time at hand I am looking for easy and cheap and reliable (I guess I can get two out of three, right?).