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Posted: 8/21/2017 8:02:07 PM EDT
To the naked eye in the dark, is there any visibility difference when looking at the LED? Also according to what I've read , gen 3 tech not as sensitive to 940, so effectively cut down on the illumination? Tell me if I'm misunderstanding please . Willing to give up a little light, for a little more stealth .  Pigs are noticing .....
Link Posted: 8/22/2017 2:14:22 PM EDT
[#1]
I can tell you for a fact that any IR light in the 850nm range is very visible to the naked eye. It pretty much looks like the red standby LED light on your TV or typical Hollywood movies when people were NODs and you see red eyes. GEN 1 requires 850nm to see a decent distance in total darkness, GEN 2 it helps in darker areas and can work without it, and GEN 3 with 850nm will make it look like the freakin sun at night. 940nm is fine with GEN 3 and it's pretty much what the built in IR light outputs on every PVS-14. Now 940nm is not so great with Gen 2 devices but still can work.

Link Posted: 8/22/2017 2:24:23 PM EDT
[#2]
Quoted:
To the naked eye in the dark, is there any visibility difference when looking at the LED? Also according to what I've read , gen 3 tech not as sensitive to 940, so effectively cut down on the illumination? Tell me if I'm misunderstanding please . Willing to give up a little light, for a little more stealth .  Pigs are noticing .....
View Quote


I had the same problem (was actually spooking pigs off) and switched to 940.  If I had to put a number to it I'd say the visible red glow of my 940 weapon light is 40% as bright as that of my 850.  Both are made by Sniper Hog Lights.
Link Posted: 8/22/2017 2:37:08 PM EDT
[#3]
Ok thank for response. That was the problem. Added supplemental light, and now they see us, or something they don't like .  Just need to make minor adjustments is all. Any particular you'd recommend based on personal experience.  Prefer adjustable beam . Rather have more flood lighting really , have a badass long distance unit so have that covered.  Thanks
Link Posted: 8/22/2017 3:11:04 PM EDT
[#4]
Link Posted: 8/22/2017 4:17:48 PM EDT
[#5]
Nothing sees 850nm monochromatic laser IR.
Link Posted: 8/23/2017 7:39:33 AM EDT
[#6]
I use a laser based illuminator on my rifles and 940nm lights on my vehicles.
Link Posted: 8/23/2017 11:03:03 AM EDT
[#7]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Nothing sees 850nm monochromatic laser IR.
View Quote
Can someone help me understand why 850nm is visible when it comes from an LED but not visible when it comes from a laser?
Link Posted: 8/23/2017 11:40:05 AM EDT
[#8]
Link Posted: 8/23/2017 2:29:41 PM EDT
[#9]
Like Hatti stated LEDs leak and some very considerably so. Some spectral charts show them going to 0 a lot sooner than what the human eye should be able to pick up, but some charts then again show them slowly getting closer to zero and leak into the visible spectrum.

You can always use a IR longpass filter to cut out unwanted frequencies. A 800nm with steep enough cut-on curve will be sufficient if the torch is not super bright.
Link Posted: 8/23/2017 2:43:44 PM EDT
[#10]
Discussion ForumsJump to Quoted PostQuote History
Quoted:


Can someone help me understand why 850nm is visible when it comes from an LED but not visible when it comes from a laser?
View Quote
Laser by definition is monochromatic wavelength output with little variation, i.e. If laser is rated at 850nm, 98% of energy emitted is from 845-855nm.

LED throws wavelength output over a normal curve centered around the stated emission, i.e. If LED is rated @ 850nm 50% of its output is centered around 850nm while there is 25% bleed down to 650nm and 25% bleed up to 975nm.

Two completely different technologies, one precise and the other broad.
Link Posted: 8/23/2017 3:09:25 PM EDT
[#11]
What's the cost on one of these lasers? Not sure if it's reasonable for my use. Might just see if I could get a 940 torch. Use one for driving ect, one for final approach.  Not a real big deal. Inside 100yds they don't have much of a chance. Just like seeing how close we can get sometimes .
Link Posted: 8/23/2017 5:35:41 PM EDT
[#12]
Much ado about nothing, the visible red bleed out from an IR LED can only be seen from a small 10-15 degree angle directly in front of the reflector, much of that depends on the design depth of the reflector being a spot or flood.
Link Posted: 8/23/2017 6:19:11 PM EDT
[#13]
Ive rigged up a few homemade halo shields for my 840nm T20s I use for coyote hunting. Toliet paper tube and honeycomb anti-glare attachement. The honeycomb on the front comes from a set of clip-on honeycomb shades for binoculars. Over kill?....maybe? It seems to work, I haven't had one notice my ir signature since.

Attachment Attached File
Link Posted: 8/23/2017 7:26:21 PM EDT
[#14]
That's a good idea. Thanks for heads up.  Probably never would have crossed my mind
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