Page 1 of 1

Red LEDs? Eh?

Posted: Sat Oct 29, 2011 7:06 pm
by Isaac
So I got a Red LED flashlight by accident. I just read around and found out that they're actually good for your vision, because they aren't as blinding. However, they also use more battery life.

I also got a green LED flashlight, also by accident. That one is suppose to be the best for wild life, because it wont scare them as much. It also wont attract bugs...

I can't find any viable source on this. Do any of you buy into this magical color stuff? If it's good enough for you, then I guess I'll keep em.

Re: Red LEDs? Eh?

Posted: Sat Oct 29, 2011 7:58 pm
by fliptw
the human eye is most sensitive to green, least to red.

rocked a red led keychain light for a good decade or so

Re: Red LEDs? Eh?

Posted: Sat Oct 29, 2011 8:11 pm
by Tunnelcat
It has to with wavelengths and the sensitivities of the 2 receptors of the eyes. To be able to see in low light, our eyes use receptors called "rods". To see in color and bright light, our eyes use receptors called "cones".

A trick to preserve night vision is to use red light, which our eye's cones can see, but is also the ONLY visible light our rods are NOT affected by. So if you want to see things in the dark, use a red light that the eye's cones respond to, and when you turn off the light, your eye's rods will still retain their night vision. Any other light will temporarily disable those low light rods, so red is the ONLY color that retains good night vision after it's turned off. That's also why it's used in film developing dark rooms.

http://www.flashlightreviews.com/qa/nightvision.htm

Re: Red LEDs? Eh?

Posted: Sat Oct 29, 2011 9:51 pm
by flip
Red is best if your in the woods and need light without being discovered by others.

Re: Red LEDs? Eh?

Posted: Sun Oct 30, 2011 5:11 am
by flip
Heh, I woke up this morning and read what I posted last night and had a real good laugh :P. LOL

Re: Red LEDs? Eh?

Posted: Sun Oct 30, 2011 7:52 am
by Heretic
I know in the navy aboard ships before you went out for night watch you stood in a room with a red light for awhile before you went out on deck. That way you could see barely on deck particularly on a cloudy night. Also the red light served as a protection device. Red lights are harder to see from another ship in the distance.

Re: Red LEDs? Eh?

Posted: Sun Oct 30, 2011 11:39 am
by Ferno
"That's also why it's used in film developing dark rooms."

that's not the only reason why it's used there.

The other main reason is, red light will not destroy the negatives or prints while they're being processed.

Re: Red LEDs? Eh?

Posted: Sun Oct 30, 2011 12:36 pm
by Krom
flip wrote:Heh, I woke up this morning and read what I posted last night and had a real good laugh :P. LOL
Yeah, I was wondering about that, were you disposing of the neighbors you didn't get along with or something? :P

Re: Red LEDs? Eh?

Posted: Sun Oct 30, 2011 12:58 pm
by Tunnelcat
Ferno wrote:"That's also why it's used in film developing dark rooms."

that's not the only reason why it's used there.

The other main reason is, red light will not destroy the negatives or prints while they're being processed.
I know that. I figured that little detail it was not relevant to the discussion of night vision. :mrgreen:

Re: Red LEDs? Eh?

Posted: Sun Oct 30, 2011 2:24 pm
by Ferno
tunnelcat wrote:I know that. I figured that little detail it was not relevant to the discussion of night vision. :mrgreen:
and dark rooms were?

;)

Re: Red LEDs? Eh?

Posted: Sun Oct 30, 2011 2:38 pm
by flip
Yeah, I was wondering about that, were you disposing of the neighbors you didn't get along with or something?
Dangit, now I gotta kill krom too =/. LOL. No, it was really more along the lines of, if the ★■◆● does hit the fan, I'll meet you in the woods. :P

Re: Red LEDs? Eh?

Posted: Sun Oct 30, 2011 3:32 pm
by Isaac
Also, why does the splinter cell guy have green flashlights on his face? It's not very stealthy..
Image

Re: Red LEDs? Eh?

Posted: Sun Oct 30, 2011 7:57 pm
by Tunnelcat
Ferno wrote:
tunnelcat wrote:I know that. I figured that little detail it was not relevant to the discussion of night vision. :mrgreen:
and dark rooms were?

;)
I did some checking and you're right. No connection that I can find to accommodating the human eye. I just assumed that using a red light in a dark room helped with keeping the operator's low light vision intact when switching between the no light and low light portions of the film developing process. Just a happy coincidence that things worked out that way I guess. :mrgreen:

Read the sixth paragraph down the page in this link:

http://thebench.ockam.com/index.php?m=200804
Isaac wrote:Also, why does the splinter cell guy have green flashlights on his face? It's not very stealthy.
Issac, it's a video game. Maybe the lenses are green because the game developers thought of those green night vision phosphors that the user normally sees from the inside and thought it looked cool if it showed on the outside of the lenses. Why the Splinter Cell character's goggles showed green always baffled me too. You'd think the enemy would see them and ruin any pretense of stealth. :roll:

Re: Red LEDs? Eh?

Posted: Sun Oct 30, 2011 8:01 pm
by Isaac
Lol, tc. Maybe they're on backwards :P

Re: Red LEDs? Eh?

Posted: Sun Oct 30, 2011 8:13 pm
by Tunnelcat
I've played those series of games and I've always wondered, since I can see those green eyepieces from the third person, why don't the other enemies see them either, even when they're standing right next to Fisher? Maybe humans can't see green eyeballs in the dark. :P

Re: Red LEDs? Eh?

Posted: Sun Oct 30, 2011 9:23 pm
by Heretic
Isaac wrote:Also, why does the splinter cell guy have green flashlights on his face? It's not very stealthy..
Image
Funny you should mention this

Image

Those work with gathering and concentrating the surround lights and stars. When I was in the service we were still IR Vision. You see red with that.