# Red LED's



## ruger357 (Feb 9, 2009)

What are they basically used for? Thanks in advance for any responces.


----------



## Marduke (Feb 9, 2009)

The short answer is to preserve night vision. You can use more red light than white and still preserve night adapted vision in darkness.


----------



## Flying Turtle (Feb 9, 2009)

No particular constructive use for me. Mostly for fun, to be honest. As a very eye friendly night or area light it's hard to beat. I suppose there have been a handful of times when I've used the red in my Proton in a situation where I've not wanted to be obviously turning on a flashlight or wanted to preserve my night vision. I still like having it available.

Geoff


----------



## Grog (Feb 10, 2009)

They are excellent at making red lines on a map disappear.....








Ask me how I know


----------



## ruger357 (Feb 10, 2009)

Grog said:


> They are excellent at making red lines on a map disappear.....
> 
> 
> 
> ...



lol


----------



## Element of Darkness (Feb 10, 2009)

Red is an excellent color to illuminate the night, but retain as much night vision as possible. Most people with red filters use them for night hikes, or walking the dogs in pitch black areas (if you live out in the sticks), etc etc. You won't see them used much in the city, with the exeption of some peace officers or other specialized use.

Personally, I do a lot of night hiking in the mountains, and I will not get on the trail without a red filter anymore. My hiking buddy and I usually night hike (or jog) in the mountains with no light for 85-90% of the hike, obviously depending on how bright the moonlight is (moonlight often times is plenty bright to see where you're going in the forest, depending on conditions). For the other 10% of the hike, we've often got red filters blazing, illuminating much of what we couldn't see with the naked eye. What's amazing though is that you can light up the forest with red light, then shut if off, and continue running or walking without breaking pace. 

To contrast this, no matter how bright the moonlight is in the forest, with an LED or incan you get this amazing wall of light when you turn the light on, then once the light turns off you are blind in a wall of darkness for 15-20 seconds until your eyes re-adjust. 

With most people living in the city, this is almost never an issue (for most folks). In the sticks, it happens all the time. If I'm in the mountains at night, I'll wear a dual red led headlamp, keep my regular bright white led EDC torch w/ forward clicky in my hand at the ready, and my backup reg white led torch in my backpack or front pocket. Hope this helps.


----------



## greenlight (Feb 10, 2009)

Grog said:


> They are excellent at making red lines on a map disappear.....Ask me how I know


Shouldn't the red light reflect off of the red lines? 

Another use would be to highlight red objects, like red chairs or a red sign.

Looking for rubies?


----------



## diff_lock2 (Feb 10, 2009)

greenlight said:


> Shouldn't the red light reflect off of the red lines?
> 
> Another use would be to highlight red objects, like red chairs or a red sign.
> 
> Looking for rubies?



It does reflect off the red lines, and the light/white background. with a red light white looks red, red looks red, red on red, red. You can't see the lines. Blue looks black. Red light can really mess with you mind at times. I would guess other narrow spectrum light sources do the same.


----------



## bullfrog (Feb 10, 2009)

ruger357 said:


> What are they basically used for? Thanks in advance for any responces.



The _PERFECT_ trip-to-the-bathroom-at-3am light!

I also use mine when I want to read in bed and don't want to bother the wife.

As far as walking or hiking with one, I'm not a fan as they mess with my depth perception...

They seem to work best for me for stationary tasks...


----------



## Blue72 (Feb 10, 2009)

bullfrog said:


> I also use mine when I want to read in bed and don't want to bother the wife.





I find dim blue light works best for this.

I used to use red light to check on the kids at night but it would wake them.

I have been using dim blue with better results ( to check on the kids not night preservation).

Test it out yourself. Shine the red light at your eyes with your eyes shut and do the same thing with the Blue light. you will notice the blue is less disturbing.


----------



## 3000k (Feb 10, 2009)

What works better, a white led with a red filter or a red led, or does it not matter?

I have a small red keychain light I keep on me, besides being red it it is bright enough for most tasks but not too bright to take away night vision. I also outfitted the dome and map lights in my truck to red leds.


----------



## mrmonk7663 (Feb 10, 2009)

We use the red lights to track people through the brush, the red helps us see the sign left behind and allows us to stay "hidden"


----------



## Guy's Dropper (Feb 10, 2009)

dd61999 said:


> I find dim blue light works best for this.
> 
> I used to use red light to check on the kids at night but it would wake them.
> 
> ...


Are you kidding?
It could vary from person to person, but blue light is almost as bad as green light for my night vision.


----------



## bullfrog (Feb 10, 2009)

dd61999 said:


> I find dim blue light works best for this.
> 
> I used to use red light to check on the kids at night but it would wake them.
> 
> ...



Interesting - thanks for the info! 

I have never owned nor tried a blue light... I think I'll pick up an F06 :huh:


----------



## Blue72 (Feb 10, 2009)

Guy's Dropper said:


> Are you kidding?
> It could vary from person to person, but blue light is almost as bad as green light for my night vision.




Like I said in my post, I do not use blue for night vision. I use blue to prevent waking others up while roaming around the house.


----------



## baterija (Feb 11, 2009)

3000k said:


> What works better, a white led with a red filter or a red led, or does it not matter?
> 
> I have a small red keychain light I keep on me, besides being red it it is bright enough for most tasks but not too bright to take away night vision. I also outfitted the dome and map lights in my truck to red leds.



It depends on what you mean by better. A white LED doesn't create much red light to pass through the filter. The plus there is is might be dimmer doing even more to preserve your night vision. Another plus is you have a white light handy if the need arises. The downside is you are burning power making all the other light that you are filtering out. A similar amount of red light can be gotten with better power efficiency from a red LED.


----------



## Moonshadow (Feb 11, 2009)

Good comparison is the Surefire L1:

Red LED version: 
High: 22 Lumens for 4 Hours
Low: 1.1 Lumens for 90 Hours 

White LED version:
High: 65 Lumens for 1.5 Hours
Low: 10 Lumens for 16 Hours

Now assuming that a red filter used on the white LED version will block about 90% of the light, you can see that you are getting a much better runtime with the pure red LED version - since all of the energy is going into red photons in the first place. 90 hour runtime on low - sweet !

Bugger - think I've just talked myself into buying another light !


----------



## Blue72 (Feb 11, 2009)

If you are looking for a floody beam get an red LED, the filter kills most of the light except for the hotspot in most case scenarios.


----------



## DreamCrusher (Feb 11, 2009)

mrmonk7663 said:


> We use the red lights to track people through the brush, the red helps us see the sign left behind and allows us to stay "hidden"



Another PA here I see. :twothumbs:twothumbs


----------



## Flying Turtle (Feb 11, 2009)

I'm thinking of a slight compromise. A Photon Freedom with an orange LED. A bit more light than red, but still easy on the eyes, and a way to dispose of a few 2032 batteries I've accumulated. Anyone here have a light with orange?

Geoff


----------



## diff_lock2 (Feb 11, 2009)

DreamCrusher said:


> Another PA here I see. :twothumbs:twothumbs



PA?


----------



## santza (Feb 11, 2009)

I have a red minimag with terralux K2 red drop-in. One of my favorite lights. 
The hotspot is quite big which is nice. Beam and light output is MUCH better than fenix l2d rb100 with red filter.
Also the color is pure red unlike fenix red filter's beam which is orange in comparison to the red LUX K2.


----------



## stefanj (Feb 14, 2009)

In Astronomy preserving night vision is the utmost in making it possible to see DSO's (faint galaxies, nebula etc.) Red is the least damaging to night vision. The average 40 year old takes about 15mins to become full dark adapted. It only takes a flash of white light to ruin this!!! I just ordered a $60 Peak Red LED for astronomy use- it is THAT important!


----------



## Blue72 (Feb 15, 2009)

santza said:


> I have a red minimag with terralux K2 red drop-in. One of my favorite lights.
> The hotspot is quite big which is nice. Beam and light output is MUCH better than fenix l2d rb100 with red filter.
> Also the color is pure red unlike fenix red filter's beam which is orange in comparison to the red LUX K2.



I think the terralux is to bright to preserve night vision


----------



## RedLED (Feb 15, 2009)

Flying Turtle said:


> I'm thinking of a slight compromise. A Photon Freedom with an orange LED. A bit more light than red, but still easy on the eyes, and a way to dispose of a few 2032 batteries I've accumulated. Anyone here have a light with orange?
> 
> Geoff


 
Yes! I have an orange Photon, and I love it. I keep it connected with my GID SAK Classic, as part of my night system.

Best,

RL


----------



## RedLED (Feb 15, 2009)

bullfrog said:


> Interesting - thanks for the info!
> 
> I have never owned nor tried a blue light... I think I'll pick up an F06 :huh:


 
Dude,

You have a great Surefire collection!! 

Why not add a Kroma to it? I have one and it is a blast around the house at night. I have a later schedule that my wife and teen, so it is handy for looking for whatever at night.

Best,

RL


----------



## Flying Turtle (Feb 15, 2009)

Thanks for the thumbs-up on the orange LED, RL. I've been waiting for someone to comment before ordering. I assume it does give a bit more usable light than a red.

Geoff


----------



## Blue72 (Feb 15, 2009)

Flying Turtle said:


> Thanks for the thumbs-up on the orange LED, RL. I've been waiting for someone to comment before ordering. I assume it does give a bit more usable light than a red.
> 
> Geoff




I believe the orange light will have to be much more dim than red light. Since orange is out of the color spectrum of which the cones of our eyes operate during scotopic night vision


----------



## Illum (Feb 15, 2009)

bullfrog said:


> The _PERFECT_ trip-to-the-bathroom-at-3am light!



I use a red E01 for the trips at night too, but I slapped my M6-1185 in the pocket in case I needed it

you never know whether you might need 1K lumens even if the room your in with your dilated pupils can only handle 1 lumen of light...:thumbsup:


----------



## StarHalo (Feb 15, 2009)

Taillights


----------



## Strauss (Feb 15, 2009)

I love my Kroma and find that I mainly use the red LED's. I have many other low output white lights, so I seem to go for the Kroma when night vision is a priority.

Trips to the bathroom at night, looking for something in the car, etc. It is also one of my favorite lights to just pick up and play around with. Having all three colors, all with mutiple output levels, is really fun. Since getting my Kroma I barely use the low-red on my Twisty anymore.


----------



## Flying Turtle (Feb 15, 2009)

dd61999 said:


> I believe the orange light will have to be much more dim than red light. Since orange is out of the color spectrum of which the cones of our eyes operate during scotopic night vision



I guess I'll be finding out in a few days which works better. I went ahead and ordered a covert orange Photon Freedom. I've got some other red lights to compare it to and will make some comments soon. I hope CFRlights ships out fast.

Geoff


----------



## ledstein (Feb 17, 2009)

You can use Red, Blue and Green to make a RGB LED flashlight


----------



## HarryN (Feb 18, 2009)

As far as colors, red/ orange is the color of most "red" traffic lights and the rear tail light on many cars.

This is a remarkably efficient color due to the very low Vf (around 2 - 2.5 volts even in power LEDs), and one of the very first LED colors in wide spread use.

I have a light with a Lux III r/o custom built by photon fanatic. The Lux III has an exceptionally large die, can handle 1.5 amps IIRC, and still has a low Vf. I had him drive it at 1 amp for long run time, and r/o LEDs tend to bge more sensitive to reduced output vs temperature. (of course, one of my kids has it somewhere now so runtime is a mute point) 

As far as light "going through the eyelids", I can agree with this. With eyes open or closed, this r/o goes right through and you cannot stand in front of it either way. 

You can shine this light through your hand no problem. With some effort, it is possible to see the shadow of the bones. Maybe someday, this will be come a diagnostic method.


----------



## Flying Turtle (Feb 19, 2009)

Got the orange Freedom today (fast service from CFR), and it compares closely in brightness to the red in the Proton Pro. Not sure if the color will make it any more usable than red, but time will tell. It's got a cleaner beam than I expected. Really no artifacts except a donut hole. Can't get it to go into the hidden 3 min. shutdown mode like the Proton, Rex, and other Freedoms will. Maybe the color LED models won't do this. Think I'll let it keep the Arc company of the keychain.

Geoff


----------



## Sub_Umbra (Feb 24, 2009)

dd61999 said:


> ...I used to use red light to check on the kids at night but it would wake them.
> 
> I have been using dim blue with better results ( to check on the kids not night preservation).
> 
> Test it out yourself. Shine the red light at your eyes with your eyes shut and do the same thing with the Blue light. you will notice the blue is less disturbing.


I couldn't agree more. Blue is highly appropriate for many low light tasks. Theatre techies probably use more blue lights during shows than all others. Human eyes can see so much more with blue that red users almost always use brighter lights in their dark adapted vision strategies than anyone else. Ironic, ain't it? True reds for rod protection, really need to be as red as the 660nm Rigel lights. At that wavelength red is at the very bottom sensitivity for shape recognition in the entire visible spectrum.

Blue may be used for many of the same tasks that people tradionally use red for and still conserve their rhodopsin, see much more than with red while running at a much reduced output level AND still be less likely to disturb others. The best ones are the ones that may be adjusted to the lowest output levels like the Rigels and the Photon Freedoms.


----------



## bshanahan14rulz (Feb 25, 2009)

while we're on the subject of red LEDs, I've always wondered, why are a lot of red LED dice inverted trapezoids? I always found that weird...


----------

