DIY UV box?

[olk]

Hello,
do you have a plan for an UV exposure box?
Should I use Philips UV-A TL-D K 30W/10 G13 (30W/05) or would LEDs fit?
The box should be compact and cost efficient.
What do you use?

best regards, Oliver

 

[glbeas]

Theres been several threads on uv lightboxes if you search you can find a few here and on the large format forum.
This is one I put together...
https://www.photrio.com/forum/threads/best-uv-light-source-led-vs-fluro-vs-hid-etc.115208/page-5

 

[wyofilm]

Theres been several threads on uv lightboxes if you search you can find a few here and on the large format forum.
This is one I put together...
https://www.photrio.com/forum/threads/best-uv-light-source-led-vs-fluro-vs-hid-etc.115208/page-5

I had been looking over LED methods to make a uv light box. The light bars from glbeas looks to be the simplest method. The was confirmed by an article by Tim Layton (https://www.timlaytonfineart.com/bl...printer-for-platinum-printing-with-led-lights) who gives a nice write up. The only downside that I can see is that the bars are sold in packs of four, but only 10 can be linked together (the number Tim Layton used). However, a work around would be to have two circuits with 6 each for a system with 12 bulbs. Or just have two extra bars up on the shelf.

I've just ordered mine.

 

[wyofilm]

The only downside that I can see is that the bars are sold in packs of four, but only 10 can be linked together (the number Tim Layton used). However, a work around would be to have two circuits with 6 each for a system with 12 bulbs. Or just have two extra bars up on the shelf.

Oops! Tim replace a 10 bulb system with 8 bars.

 

[fgorga]

As a point of reference...

I have an exposure box large enough for a 16x20 contact printing frame with four 24 inch LED bars in it... the ones that Gary mentioned (that I told him about in the thread he cites). These bars make wiring up a unit trivially simple and painless.

The unit itself is just a simple plywood box with one side left half open. The opening is covered with a strip of black cloth. My unit has a few 3/inch holes on each side for ventilation. These are leftover from when the box had fluorescent bulbs and U don't think the are necessary with the LED strips. The box is painted glossy white inside.

The height of my box is about 8 inches which puts the glass in the frame between 6 and 7 inches from the LEDs.

My standard exposure time for traditional cyanotype with this unit is 7 min. I have not tried other processes yet.

The light is uniform enough to make an 11x14 inch image in a 16x20 frame. I have not tried a larger image. Although, I use it mainly for 8x10 inch or smaller images.

 

[wyofilm]

As a point of reference...

I have an exposure box large enough for a 16x20 contact printing frame with four 24 inch LED bars in it... the ones that Gary mentioned (that I told him about in the thread he cites). These bars make wiring up a unit trivially simple and painless.

The unit itself is just a simple plywood box with one side left half open. The opening is covered with a strip of black cloth. My unit has a few 3/inch holes on each side for ventilation. These are leftover from when the box had fluorescent bulbs and U don't think the are necessary with the LED strips. The box is painted glossy white inside.

The height of my box is about 8 inches which puts the glass in the frame between 6 and 7 inches from the LEDs.

My standard exposure time for traditional cyanotype with this unit is 7 min. I have not tried other processes yet.

The light is uniform enough to make an 11x14 inch image in a 16x20 frame. I have not tried a larger image. Although, I use it mainly for 8x10 inch or smaller images.

Thanks for your remarks. I am excited to build a box using the bars you highlighted. The box that Tim Layton built using the same bars (8) allows him to make 20x24 prints, I will build the larger box and hope that I will someday make a print that large!

 

[Patrick Robert James]

The simplest way I think is the light bars. If you want something that prints super fast though and have a lot of extra time to make one, using strip LEDs will do it. I made one a couple years ago and my exposure times with cyanotype and digital negs from a Canon pigment printer fall between 1:30 and 3:00, with most being 2-2:30. Super fast. That is more UV than the sun, so be careful... Can't tell you how nice it is to have times that quick. I think the total cost of mine was maybe somewhere around $150 or so all together. I think the light area is around 17x22 for 13x19 negs. I kind of wish I would have made it a touch bigger for even larger negs. I was going to do a write up about it but then I saw those light bars and I figured no one would be interested since that is such a simple way to do it. I had to solder for hours......

 

[glbeas]

I had been looking over LED methods to make a uv light box. The light bars from glbeas looks to be the simplest method. The was confirmed by an article by Tim Layton (https://www.timlaytonfineart.com/bl...printer-for-platinum-printing-with-led-lights) who gives a nice write up. The only downside that I can see is that the bars are sold in packs of four, but only 10 can be linked together (the number Tim Layton used). However, a work around would be to have two circuits with 6 each for a system with 12 bulbs. Or just have two extra bars up on the shelf.

I've just ordered mine.

I hung a powerstrip in my box and plugged eight strips linked in twos, works great.

 

[wyofilm]

Theres been several threads on uv lightboxes if you search you can find a few here and on the large format forum.
This is one I put together...
https://www.photrio.com/forum/threads/best-uv-light-source-led-vs-fluro-vs-hid-etc.115208/page-5

To update this thread - a couple of days ago I put together an 8-bar light box much like described above. Very simple to do and the results are great. Although, I've only tested it with cyanotype at this point. Depending on the neg, exposure times are in the 2-4 minute range. If anyone has an inclination to build a UV box with LED lights, I can highly recommend the Barrina light bars (https://www.amazon.com/gp/product/B071NT6189/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1)

 

[saddlemeyer]

To update this thread - a couple of days ago I put together an 8-bar light box much like described above. Very simple to do and the results are great. Although, I've only tested it with cyanotype at this point. Depending on the neg, exposure times are in the 2-4 minute range. If anyone has an inclination to build a UV box with LED lights, I can highly recommend the Barrina light bars (https://www.amazon.com/gp/product/B071NT6189/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1)

It's been a while, but just wanted to see how this UV box is working for you? I'm thinking about building one.

2-4 minute cyanotype exposures sound dreamy - how much space did you leave between each bar?

Thanks!

 

[fgorga]

It's been a while, but just wanted to see how this UV box is working for you? I'm thinking about building one.

2-4 minute cyanotype exposures sound dreamy - how much space did you leave between each bar?

Thanks!

Not @wyofilm but I can chime in... I have upgraded the box I described above (post #5) from 4 strips of LEDs to eight strips. The strips are mounted on roughly 3 inch centers.

My exposure times are 4-5 min for traditional cyanotype and 7 min for salted paper.

This approach seems to be gaining popularity, see: https://www.alternativephotography.com/diy-uv-light-boxes-alternative-photography/ for a pretty good set of build instructions.

 

[koraks]

I've moved towards smaller-sized COB LEDs because they give much better collimation, which means sharper prints especially on thicker media. For some printing processes, this doesn't matter that much. For some processes, like carbon transfer using halftone screen negatives, it's the way to go as strip lighting doesn't even work!

The gist of my comment is that when it comes to UV LED exposure units, it's wise to at least take stock of the present state of technology before jumping on a 15-year old concept.