It’s a lens that only allows the infrared light to come thru. Used for light vision. Replaces the lens on your flashlight, or is a lens cover that attaches to your light.
Ohhh, I've read about doing that with film negatives.
Only problem is that I read SMD LEDs like Cree's won't work and those are the only lights I have.
Also, my SD Card (aka "film") wasn't playing nicely with letting the IR light though... (I don't have film) :P
I also only have lights that will get hot and likely overheat if I leave them on overnight.
Would rather just make a cheap array from LEDs and wire.
Have you checked the available arrays?
I have seen them on eBay quite often…
The available 3AAA lights often have just a PCB and no real driver, so it depends on the forward voltage if it works
Do you plan this as a mounted device or as a mobile flashlight.
I was planning on having it mobile. Attaching to the tripod mount of the camera so I can take it off.
Do you recall how much the 3aaa arrays were on ebay? I'm seeing like $30+.
Yeah, White LEDs won't put out the IR you need to use through a filter. Incan bulbs on the other hand, are IR blasters. If you found flashlight that used 5mm RED LEDs, you might be able to just swap with your emitters. Several years ago, I built a board with about 20 5mm IR LEDs to use with some IR photography and got pretty poor results. Not enough throw for any distance illumination.
You may prefer to try one of these IR P60 Drop-ins:
http://dx.com/p/high-powered-3w-infrared-ir-drop-in-module-for-wf-502b-style-flashlights-8-4v-12625
...or build something up yourself using some of these higher-powered emitters:
I haven't gotten to play with any of these myself, but am planning on installing a security DVR system in the near future and want to build an IR floodlight for the yard. Make it look like daytime outside through the cameras... 
These arrays for cameras are often 12V.
There are also neat 12V spotlights available. 10$ ir spotlights for cameras
But they are nice and fairly cheap, but without battery…
Maybe a normal flashlight with a power led.
There are 1W infrared LEDs on stars available or of course some nice LEDs like a oslon black.
For the oslon check this
Maybe a AA light with a boost driver should give a lot light in a small form factor.
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I do not know if a visible light LED produces IR, but if you change your mind want to fool around with IR filters, here are a couple inexpensive ones:
http://www.bhphotovideo.com/c/product/102762-REG/LEE_Filters_87P3_3x3_Infra_Red_87.html
I have used ones similar to these for IR photography. An incandescent bulb will produce IR through one. Get a wavelength that matches your viewer…
With leds, only IR leds will produce IR.
Filters will not work.
Here is the series wiring for IR leds to replace the led in that 9 led light.
It will be ok if you skip the resistors pictured.
I bought 4 SolarForce L2P with 4 930nm P60 drop-ins.
4 are no where enough light to make a dent when used on a cloudy day for portrait photography.
2 are too much for night-time plant photography.
If I am to repurchase my setup, it would be 2 SolarForce L2N and 2 (cheap) SolarForce IR drop-ins.
Flash and strobe yield a lot of IR light and are what I use now for day time portrait photography.
(930nm IR filter. Normal lens (50mm f/1.2). Full spectrum modified sensor (5D II Canon).)
I screwed up my IR flashlight test shoot. The torches were too bright and I couldn’t reduce output enough, and the background was too dark, and she moved slightly in 1 second exposures.
Mercifully, Holly didn’t make me answer for it.
1-second @ f/1.2 with a 50mm at 0.5 meter. 2 IR L2P being waved around. Having plants as subjects is less stressful, and I had time and multiple outings to debug issues.
Unless your camera is known to be particularly sensitive as high as 930nm - 940nm you’ll get a lot more light from 850nm. 850nm will have a slight visible dim red glow.
Thanks for the diagram.
Will that actually work with IR leds?
Did you actually disassemble your own $3,000 camera?
I'd be terrified of breaking something or getting dust in my sensor.
Same thing i've came across too, everywhere says 850nm is the IR wavelength you want for imaging.
850nm is also what my camera has built in. I can see the red glow.
The 1 built in LED gets me to 10-15ft in complete darkness indoors.
I live in a city and haven't got to try it without small amounts of street and house lights around me.
Would assume that with less smooth surfaces(walls) for the IR light to reflect off of, it would result in a significantly reduced ranged.
I am going to use the IR Array for 0 lux recording, and 850nm LEDs... I probably should have mentioned that.
Can I power one of those 12v ones from a battery? or better yet 3-4x 18650s?
I guess you could build a power supply on your own, there are also some nice step up modules from china out there, so you could use one or two 18650 and a module for 12V or so.
I would also try to open the light and check how the circuit in it looks like, maybe it is even easier to power it.
I guess size doesn’t matter if you consider this?
Yep, the diagram is for IR leds. LED series/parallel calculator
That would be better. You can get larger arrays of leds. Some have light sensors that turn them on only at night. Like Werner said there are voltage step up modules. Lots of sellers on ebay.
I need to be careful how I say this... size doesn't matter to me.
Cost does though.
Youtube video on how to build a 5 IR LED for under $15 from radio shack.
Will be less if I buy the materials online instead of from radio shack.
Spotlight 10$
Step up 3.5$
Battery case 5$
—————————-
. 18.5$
And you would get 30-40Leds….
I have no experience with this ir LEDs but five LEDs sounds not so bright…
Try ebay for better prices. What country are you in?
ir led module ebay $2.79 36 leds.
48 leds module in a nice enclosure ~$8
Does it need to be battery powered? You could get an 12v AC adapter. You could extend the cable a bit if needed.
$2.17 for a LM2577 Step-up Module on ebay
For hunting with night vision I turned the lens on an it laser backwards and defocused it works great with gen2 googles
Not sure of your use though if it were to be pointed at someone it would be bad
Prior to hunting I also snap some ir chemlights for distance marking
If I get one of those LM2577 Modules, I would just solder the wires from the battery to the +/- In on the module and the illuminator to the +/- out?
How many 18650s would I need to wire together? more than 12v in total nominal voltage?
LM2577 input voltage : 5V-32V
Need two 18650s in series. You can use a couple pairs (each 2 series pair in parallel with other pairs). Not sure how many is needed for a decent runtime. Use only batteries with quality protection. NCR18650B Protected 3400mAh Series batteries must have real protection.
You do need a multimeter to set the LM2577 module’s voltage to 12v since its adjustable.