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

Vaughn

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wolfe23c said:
I also use a 250w metal halide lamp!
Click to expand...

I used 750W self-ballasted mercury vapor lamps...look like light bulbs on steriods! Very portable for workshops, etc.
 

SadowskiPL

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Hey there,

I thinking about go back to making prints in Gum Bichromate, Carbon and Cyanotype.

Maybe this LEDs will be OK to use ?
http://www.ebay.com/itm/10W-High-Po...hash=item33b1d0232c:m:mw7Gg5PE-b0KecodDtQE2gw
http://www.ebay.com/itm/1PC-28x3w-8...440840?hash=item5d63b00e08:g:JhQAAOSwOfxXA7m9
http://www.ebay.com/itm/1PC-28x3w-8...406249?hash=item5d63af86e9:g:dqEAAOSwWBJXA7rq
http://www.ebay.com/itm/High-Qualit...hash=item3aae25f6a7:m:mToBgkrtgYss_C-2Am10uRA
There is a variety of wavelenght to choose.

Also think about to build Vaacum frame for A3+ format.
 

timparkin

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I looked at these but the smaller ones we reviewed as being 'variable' to say the least (i.e. many broken, many underpowered. They are basically seconds from other processes). The larger panel would have to be used as a point source and there were going to be problems with localised heat. The strip LEDs meant you could put them close to the film and not waste any light and the quality is very consistent (I only lost one 40cm strip out of 10m). Also the heat handling is spread and I was able to heatsink and fan this larger areas.

Good quality high wattage units were a lot more expensive ($700+)

Tim
 

SadowskiPL

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Can I find somewhere some tips about making vacuum frame ?

But this HiPower Multiled UV source with80W should be ok with 390-395nm spectrum ?
 
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SadowskiPL

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Hey,

1. What glass can be used besides of quartz glass (expensive as HELL) ?
2. What valves and seals do you used?
3. Wood or metal ?
4. 50l/min pump is ok ?
5. What to use for back mat ? Gum, neoprene, something else ?
6. i was thinking about unit like NuArc, 100W UV LED 390-395nm above vacuum frame. Or to make it from that UV Strips from 5050 UV leds.
 

Peabodius

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1. I used a sheet of acrylic, which is not supposed to work. Technically it blocks a certain amount of UV light, but I have plenty of bichromate prints that are proof that it works. It did lengthen my exposure times a bit. My vacuum frame is big enough to print 40"x50", and the sheet of acrylic cost me about $125 with the shop cutting it for me.
2. I bought the fittings and hose from Best Value Vacs. The 1/4" hose attaches to the vacuum pump on one end, and into a valve (to shut off air flow) and then a fitting that I attached to the wood frame using an adhesive caulk.
3. I used wood, simply because it was easier for me to construct and because a metal frame in the size I intended to build would be extremely heavy. I wonder about long term wear and tear, but it's functional.
4. I have no idea! Info on appropriate vacuum pumps for contact printing is very scarce. I bought this from eBay, and it's doing a satisfactory job on my monster frame. I'm confident that something similar would be perfectly appropriate for a smaller frame.
5. I needed something very large but cost efficient. I cut a shower curtain liner to size and duct taped it to the base of the frame at the edges. Works like a charm.
6. I'm using fluorescents, and get good results. I do warm the bulbs up before the exposure, and maybe an LED would save you the trouble. But I don't have any direct experience with the UV LED lights.
7. There isn't a #7, but it should be sealing the frame. I tried weather stripping, and didn't have any luck. As a temporary solution, I'm wrapping a strip of duct tape around the outside of the frame and then remove it after the exposure. I'm sure more respectable solutions are out there, but you gotta love duct tape.

Here's a picture of the frame and UV box. Definitely designed for functionality over aesthetics. The "pizza oven" style UV box lets me slide the frame in and out without having to lift it.

Hope that helps!
~Josh
 

Vaughn

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Whoa! You can buy a lot of something else for that! I do not even like the LEDs being on the bottom -- awkward for alt processes, tho it seems to work fine in the video for screen printing.
 

David Knierim

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Agreed - do be careful about efficiency. UV LEDs range from 2% to just over 40% efficient (light output power / input electrical power). I have a few small 1W 395nm LEDs that are about 40% efficient (purchased from Mouser for about $8 each) and a generic 50W 395nm LED from EBay (China) that measures about 15% (7.5 watts of light output) costing $23. I have three others on order from EBay, ones that list the brand of LED die used (EpiLEDs and EpiStar). These should be close to 40% efficiency if they really use the indicated brand of die internally.

David Knierim
 

cliveh

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I bought a facial UV tanner 5 tube light off ebay for £25 and modified its time clock so I can expose in the middle of the night without being in the room. Works fine.
 

glbeas

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My fluorescent black light bank is breaking down on me, cheap chinese electronics. Whats the latest in led black light arrays that can be DIYed and how good do they work? I saw a lot of led black lights advertise but nothing I could see using.
 

fgorga

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glbeas said:
My fluorescent black light bank is breaking down on me, cheap chinese electronics. Whats the latest in led black light arrays that can be DIYed and how good do they work? I saw a lot of led black lights advertise but nothing I could see using.
Click to expand...

About six weeks ago, I re[paced the very old and cranky fluorescent tubes in my homemade exposure unit with with LED strips. Specifically these: https://www.amazon.com/gp/product/B071NT6189

They work like a charm for cyanotypes...the only process I have tried with them thus far. They are about twice as fast as the old tubes were.

I have the four strips spread out in a box that is large enough for a 16x20 inch printing frame, but have only made 8x10 inch prints in it thus far.

There is no sign of any unevenness in the exposures at 8x10 but one could easily add a second set of strips if needed. One of the advantages of LEDs is the lack of heat being given off. Thus I'd not hesitate to add another set of four LED strips if I find it necessary. My unit is painted glossy white inside.
 

glbeas

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Thanks, thats exactly the kind of thing I was looking for. Since it comes in packs of four I ordered two sets so I could outfit the exposure frame fully.
 

glbeas

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What kind of spacing between the strips did you use and how far from the contact frame did you have? Mine was pretty close, not sure if Ill need to change the spacing on mine.
 

fgorga

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glbeas said:
What kind of spacing between the strips did you use and how far from the contact frame did you have? Mine was pretty close, not sure if Ill need to change the spacing on mine.
Click to expand...

The inside dimensions of my box are 20" x 28" x 8". The four LED strips are placed roughly 4" apart and 4" from the sides of the box.

I used to have six 24" fluorescent tubes in three fixtures in there.
 

glbeas

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Thanks, looks like my rig is going to be pretty high powered with all the strips in.
 

glbeas

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Van Dykes are about as easy as it gets, probably about as easy as cyanotype, just different sensitiser.
 

MattKing

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glbeas said:
Im doing van dyke process. Any idea how that would compare?
Click to expand...
Just asked a friend of mine who does both. He ends up with similar exposure times for Cyanotype and Van Dyke Brown work, using his older UV light box using the fluorescent tubes.
 
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