Cyan LED Uses?

[maxspeeds]

Ok, this may be a bit premature to post, as I just received a Q2H lux I cyan emitter today, and have been playing with it for only a few hours. Although the color is very beautiful and unique, I've been searching in and out of CPF for a practical purpose to Cyan light.

So far I have found that it is useful for reading through Night Vision equipment. Something about our eyes being more sensitive to the blue-green spectrum and able to discern small numbers and letters alot easier when dimly light through this color.

Outside of Night Vision equipment, are there any other practical uses? I've also read that it is useful for hunting blood trails, but that doesn't seem to be accepted 100% by everyone.

I can tell you one thing. the light really irritates my eyes. It irritates it more than white light. It seems it is very good at killing your night vision :naughty:. And, this makes sense since it completely lacks red (the best color for retaining night vision). Maybe it is good as a personal defense weapon at night? Hopefully someon can shed some light on the Cyan mystery lovecpf

 

[space]

It kills your night vision because it emmits light right in the midle of your night vision responce, thereby lowering your eyes responce.


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[Daravon]

There are many color photographic processes that use cyan light. Traditionally, a color enlarger has cyan, magenta, and yellow lights that can be varied for appropriate color balance. Color photography has pretty much gone head-over-heels digital, but anyone looking to do optical prints would definitely be interested in cyan LEDs.

 

[NateTheGreat]

If you study calcium levels in cells, the color is good for single wavelength fluorescent calcium dyes like Oregon Green Bapta-1 or Fluo-3!

 

[greenlight]

You're not supposed to look AT the light!!!

Seriously, though, at very low levels the cyan light appears brighter than you would expect.

 

[Greg G]

A member posted recently that his cyan light cut through rain very well. That's why he liked his. :candle:

 

[Canuke]

It kills your night vision because it emmits light right in the midle of your night vision responce, thereby lowering your eyes responce.


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The flip side of that is that if you are night adapted, you can illuminate *huge* areas with a one-watt LED. Just be careful not to hit something close by with your eyes open

 

[2xTrinity]

The flip side of that is that if you are night adapted, you can illuminate *huge* areas with a one-watt LED. Just be careful not to hit something close by with your eyes open

IMO in this case you're still better off with a plain old white LED. why? Not everything you're interested happens to reflect cyan light -- for example, red dirt, and many green tree leaves don't reflect cyan very effectively.

When you are dark-adapted, your eyes really don't perceive colors (at the low levels of illuminaion I'm talking about) but in order for you to see anything the light still needs to be at the correct wavelengths to be reflecting reflecting off of the surfaces you're interested in seeing, in such a way as to be creating useful contrast. This means a broad spectrum, rather than a single color is best. With red you'll see maybe the ground but not tree leaves. With green you'll have the reverse situation. With cyan or blue you'll see some flowers and white surfaces very well, but not much else. With white light, you can see some light reflecting off of just about everything.

My very favorite light for seeing outdoors at night in very low illumination is actually 4000k white. It is actually solar powered, and is designed specifically for this purpose. It is called the moon.

On days when this "moon" doesn't work well enough for my liking, I use an LF2x, with a Neutral white LED Cree 5A LED, running at 1/3rd lumen. Enough to comfortably night-hike with with dark-adapted eyes, and diffuse enough that I don't dazzle myself.

 

[BVH]

Here's a great "use" for cyan emitters.

Well, maybe it's not a "use" for them but it sure is eye candy. This is Mac's original photo of the light I bought from him. The four Q2HC "to die for" cyan emitters are just gorgeous when driven at 1 Amp+. All the green is gone, just pure Cyan.

 

[Phaserburn]

I have a light called the Cyanator. It's a lux3 cyan direct driven from an 18650. Draws 1.4A for around 10 mins before settling into 1-1.2A range.

It-is-blinding!

 

[Canuke]

When you are dark-adapted, your eyes really don't perceive colors (at the low levels of illuminaion I'm talking about) but in order for you to see anything the light still needs to be at the correct wavelengths to be reflecting reflecting off of the surfaces you're interested in seeing, in such a way as to be creating useful contrast. This means a broad spectrum, rather than a single color is best. With red you'll see maybe the ground but not tree leaves.

Dark-adapted night vision doesn't perceive red at all, whether it's there to be reflected or not. Only the green-to-violet band is used. So, white is less effective in this context to the extent that it puts out red light.

Also, since our vision is monochrome anyway when night-adapted, the contrast that results from using a narrower-band emitter might work more to our advantage than the more even shades of grey we'd see with a wider-band emitter, since contrast becomes more important as an information source in monochrome vision.

That being said, it depends on the application; for general seeing purposes, cool white and pure cyan work equally well for night-adapted eyes. Warm white LED's and incandescents, which put more energy into the red band, less so.

 

[Canuke]

I have a light called the Cyanator. It's a lux3 cyan direct driven from an 18650. Draws 1.4A for around 10 mins before settling into 1-1.2A range.

It-is-blinding!

I have an old Mr. Bulk "Eye-Cryin' Cyan" with a Lux 5 emitter, that still holds its own for output even with modern Seoul and Cree lights. It is a true cyan, sitting right on the border of where I start to call a light blue instead of green.

Current Lux III's of the same color nowadays, however, are binned as Q6JB *blue* emitters. I have several of these. The ones now sold as "cyan" (xxxC), including the Q2H I have in a modded Fenix, are all green (albeit "traffic-light" green) to my eye.

Funny thing, speaking of traffic lights, the green seems to be migrating towards the blue end of late; several of the new green LED's I saw in Canada last Christmas were really starting to look cyan instead of green, and I just noticed some similar cyan lights just down the road from here in Toluca Lake.

 

[BVH]

The last 10" traffic light green LED module I looked at in the Traffic Signal maint shop for City of Burbank used two distinct colors of leds in it's grid. Relatively speaking, there was a green and a blue-green emitter arranged symmetrically in the circle. Very obvious up-close but when 20' away they blended into an overall blue/green light as compared to the original LED modules Burbank used which look green by comparison.

 

[GarageBoy]

High visibility marker light?

 

[Sub_Umbra]

...So far I have found that it is useful for reading through Night Vision equipment. Something about our eyes being more sensitive to the blue-green spectrum and able to discern small numbers and letters alot easier when dimly light through this color...

Go back and re-read the posts that gave you that impression. The exact opposite is true and it's very well documented.

For the most part, NV gear can't see cyan at all, unless it's pointed directly at the sensor -- and the operators happen to be paying attention at that moment.

 

[LukeA]

A member posted recently that his cyan light cut through rain very well. That's why he liked his. :candle:

That's because the back scatter looked dim because the eye is so insensitive to cyan.

 

[greenlight]

That's because the back scatter looked dim because the eye is so insensitive to cyan.

 

[Sub_Umbra]

That's because the back scatter looked dim because the eye is so insensitive to cyan.

The human eye is actually pretty HOT in the cyan range for scotopic vision:

The 490-495nm representation on the scotopic curve above is near optimal for shape recognition.

http://hyperphysics.phy-astr.gsu.edu/Hbase/vision/bright.html

 

[LukeA]

The human eye is actually pretty HOT in the cyan range for scotopic vision:

The 490-495nm representation on the scotopic curve above is near optimal for shape recognition.

Your point being? Using a flashlight of middling brightness within 200 feet or so results in illuminances high enough to push the eye into photopic vision, making the cyan much less useful than white (or green, or yellow, or orange).

 

[greenlight]

The original question is not what cyan is not good for, but what are its uses.

I find it particularly pleasing, and I appreciate seeing it used in light shows. It appears very bright and is useful for effects with scattered beams like mirrored balls or other effects.

Not everything HAS to be white. Some people like to mix the colors up, and cyan is a good choice.

I have an Inova X1.v1 that's waiting to be modded with a cyan LED. I'm looking forward to seeing that. I expect that it will appear really bright, and no one has ever seen that before, so it's a good conversation starter.