Red vs. Amber/Orange LEDs

Hi!
I've been recently exploring the possibility of getting a light with either red or perhaps orange or amber LEDs. The idea was to preserve night vision, as I'm rather fond of hiking and sometimes I'd like to preserve my night-adapted vision.
The question is: do amber or orange LEDs have the same usefull feature of not destroying night-vision? Is there a significant difference between them regarding this aspect?

Thanks!

DragonFlame wrote: "The question is: do amber or orange LEDs have the same usefull feature of not destroying night-vision?"

No...
probably not - depending on your definition of night-vision.

True scotopic night vision - or rods only vision - Red is the only color that will not interfer with the vision since the eyes' rods are not sensitive to wavelengths longer than about 650 nanometers. However you should note that some people have difficulty seeing well under red light especially people with or nearing presbyopic or "old-sight" (ie: needing reading glasses) .

However just being able to see in the dark - may not be true scotopic night vision - eg: anytime one can see any color, no matter how dimly, by definition one is not using pure scotopic night vision. Since the eyes' cones are responsible for color vision - so seeing any color means the cones are being used - so NOT scotopic vision.

Under these circumstances it's the dimmness of the light that's more important - and color is more a personal preference. I like Yellow because I seem to see well under dim yellow than any other color - whether that's physiology, psychological, conditioning or even fantasy - is not important - as long I think I see better.... I see better.......

Some useful references -

USAF Flight Surgeon's Guide Chapter 8
(Night Vision section is just past 1/2 way down)

Sticky: Human Night Vision Preservation

Thanks a lot for showing me the sticky thread! I'm researching the matter right now.

In my experience, and from what I've read, red light is kind of a special-purpose light for protecting dark-adapted vision that is not real useful for much else.

You have some cells in your eyes that are not sensitive to red at all. If you only let red light into your eyes, those cells become dark adapted. The cells that see red light lose their dark adaption, but they readapt relatively quickly.

By dark-adapted I am talking about retinal changes that take nearly a half hour, not just dilated pupils. I get the impression that when a lot of people talk about dark-adapted vision, they think they are referring to retinal changes, but really they are talking about pupil changes.

Dim light of any color will preserve dilated pupils. Only red light preserves dark-adapted retinas.

The reason I say red is not real useful for much else is that your eyes are about a bejillion times more sensitive to blue-green than to red. You can have a red light that is maybe even a little bright for reading, but when you try to walk around with it, the light seems to just evaporate. A yellow light, for example, that is maybe a little dim for reading can be used just fine for walking around when it is really dark outside.

If you use a dim yellow light when your eyes are dark-adapted, you will preserve most of your night vision, but not as much as if you use red. Probably most people will not see any difference unless they are doing something really vision-intensive, like star gazing. You'll definately notice the difference between dim yellow or amber and red then.

Another consequence of the eye's inability to see dim red light is that you can use it to avoid being seen by others. You can use about 100x more red light than cyan before you will be seen by an observer. Of course the military situation is a little different, because of the different sensitivities of night vision devices.

So if you are doing astronomy or similar, use red. If you are walking around, use yellow, or maybe even a dim cyan. A lot of sources indicate that yellow light is most easily focused, so produces less eye strain when reading.

I like:
- red for astronomy
- yellow for reading
- cyan for seeing things in the distance with binoculars

Colored lights are just more fun anyway.

Scott

Note: Yellow is useful outside since it attracts less bugs.

Bugs that bite are usually attracted by your scent or CO2 emission, not by light.

I use a Red/Orange Lux III direct driven in a 2D Mag for hiking and hunting (that is getting to and from a hunting spot in the dark) at night and I found it works very well. I notice the white light from other flashlights really blinds me for a few moments but the red light does not (unless I look right into the beam).

This R/O Lux III is very bright and throws well with the big Mag reflector. It picks up trail markers and reflective signs half a mile away! If you adjust the focus to flood, you get a very large and useful area of light with a little bright spot in the middle. I plan you buy a MOP (mild orange peel) reflector to smooth out the beam more. The 2 D alkaline batteries give a 10+hours of runtime before they start to dim noticeably and close to 20 hours of useful light. Try that with incan!

I bought a Red Lux III as well and just haven't used it yet. The R/O worked better than expected.

For astronomy some people believe amber to be superior.

See the following

http://www.iceinspace.com.au/forum/archive/index.php/t-146472.html

Wow this Thread is 15 years old... :thinking:

...but I agree amber is also fine to prevent night adaption, like red and also green. Often the color that is used depends on what you are doing. Red might be a problem reading maps...

Red is for overall low light situations, blue can be used for spotting blood (looks black), green is used for reading maps, and amber I think is used for foggy/ smoky/ visual acuity. If I remember correctly.

> He also argues that low-level amber light allows our eyes to recover their night-vision sensitivity as quickly as red light

I think that is not correct

here is why
when using red light there is no degradation of rhodopsin

with other colors, at low enough levels, the destruction of rhodopsing is small, but it is still reduction of rhodopsin

only red does not degrade rhodopsin
which means red can be used at brighter levels than other colors, and still have no impact on rhodopsin levels

I'm glad this was bumped, I've been very curious about this.

All I know is I find the red to make my eyes feel fuzzy and blurry and it's overall unpleasant while the amber gives better visual acuity and is more comfortable. That's not scientific it's just my preference. So for me, advantage: amber.

An oldie, but the science hasn't changed...

http://articles.adsabs.harvard.edu/...=NO&data_type=GIF&type=SCREEN_GIF&classic=YES

Count me in on team Amber!

wacbzz said:

An oldie, but the science hasn't changed...

Click to expand...

thanks for the article link



https://webvision.med.utah.edu/book/part-viii-psychophysics-of-vision/light-and-dark-adaptation/
"When the rod mechanism takes over, coloured test spots appear colourless, as only the cone pathways encode colour."

Looks like I need to find some amber lens to go with my red ones.

Havok said:

Looks like I need to find some amber lens to go with my red ones.

Click to expand...

try a green one too

share what you learn

bottom like if if a light (of any color) is dim enough that you cannot see colors.. then your night adapted vision is being preserved.

===

Jetbeam Stepless Rotary
2019 RRT-01 mod to Red LED 620nm

!!

!!

In actual use the red beam is Very Throwy, I can easily see a wall 15 yards away in the dark using only 10 lumens Red.

I can also see the wall using 10 lumens from my sw45k in an RRT-01, but it is dimmer, and the hotspot is larger.

and when I measure the hotspot on a wall up close, with both lights set to 10 lumens, the hotspot from the red LED is TWICE as bright as the hotspot from the sw45k

the red LED has a Much more focused hotspot.
sw45k on left:


sw45k:


620nm Red:


I like the Red! The color is rich and I can easily see with it.