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Thread: Inretech 2AA Cyan?

  1. #1
    Flashaholic* StoneDog's Avatar
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    Default Inretech 2AA Cyan?

    Has anyone ordered/reviewed one of these? The Inretech site lists them as giving 30 lumens vs the white's 18(?).

    Is this a noticeable difference given the differences in color?

    Also, how "useable" is cyan vs pure white? I'm looking for a nice, small light that may not have the throw of, say, my 4AAA double barrel Energizer, but will be plenty bright for changing a tire, navigating in the woods, clearing my house, etc at night.

    I'm looking for a no hassle EDC and this one *feels* like it will be better than the 4AAA I mentioned above... Actually, will the cyan LED w/ collimator "throw" as far as the 4AAA DB if I feed it lithiums?

    Thanks for any help.

    Jon

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    Flashaholic* StoneDog's Avatar
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    Default Re: Inretech 2AA Cyan?

    Thanks Scrimmy and Mike.

    I take it then (and yes, I've read this all over the place, I just don't want to believe it) that at say 30 feet the 2AA drop in (Cyan or otherwise) is going to work more like a flood light with not much of a hotspot?

    Again, I'm comparing this to the 4AAA DB which seems roughly equivalent to a 2D Mag at 30'. By way of a few different comparisons I take it the 2D puts out roughly 15 lumens vs the Inretech's 30. I guess the difference is how focused those 30 lumens are (or aren't)?

    Forgive the newbie questions, but this is really bugging me. [img]images/icons/smile.gif[/img]

    Jon

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    *Flashaholic* McGizmo's Avatar
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    Default Re: Inretech 2AA Cyan?

    Mike,
    Thanks for providing the spectrum and sensitivity graph. I have a question as a result of looking at the color graph. The 1 W luxeon Cyans I have from Arc in LS's do appear to be at the 550 nm range. However, I have a couple 1 W batwing stars as well as some 5W HD's that seem to fall around 500 nm which is where I had always assumed "Cyan" resided??!? Isn't the combination of green and blue supposed to be cyan? Are we seeing Cyan's from Lumiled that are coming from either side of the green spectrum? This certainly explains one Arc SLS that is greenish yellow in color.

    Illumination please [img]images/icons/grin.gif[/img]

    - Don

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    Default Re: Inretech 2AA Cyan?

    The XXX-nm refers to the wavelength/frequency of the LED

    But from company to company each of them will assign "colors" to them differently, one company may put out a 500nm LED and call it Cyan while another company may put out a 550nm LED and call it Cyan also, even thou it is a different wavelength/frequency and color

    But, its easier to describe colors to people if you use terms like "Green" "Cyan" "Red" "Orange", etc - instead of the wavelength/frequency

    Like going into a paint store and asking "Do you have any 620nm Paint ?"

    The human eye seems to peak at the greenish-yellow portion of the spectrum, but as before - illuminating something with a non-white color will cause everything to be rendered "wrong", its the same effect that you get when you try to take pictures using a film camera under Flourescent lighting

    Mike
    www.inretech.com

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    Default Re: Inretech 2AA Cyan?

    Originally posted by McGizmo:
    Mike,
    Thanks for providing the spectrum and sensitivity graph. I have a question as a result of looking at the color graph. The 1 W luxeon Cyans I have from Arc in LS's do appear to be at the 550 nm range. However, I have a couple 1 W batwing stars as well as some 5W HD's that seem to fall around 500 nm which is where I had always assumed "Cyan" resided??!? Isn't the combination of green and blue supposed to be cyan? Are we seeing Cyan's from Lumiled that are coming from either side of the green spectrum? This certainly explains one Arc SLS that is greenish yellow in color.

    - Don
    <font size="2" face="Verdana, Arial">I've been wondering about a related question for a while now. According to eye sensitivity charts, right around 505nm is where our eyes are most sensitive when completely dark adapted (scotoptic). However, in most situations, our eyes are still using their day vision (photoptic) and are most sensitive to around 550nm. 505 is supposed to be closer to cyan and 550 is closer to green. Using this reasoning of mine, I'm very surprised more people don't use the greens rather than the cyans. Both Nichia and Lumileds have products that fall in nicely in those two categories, yet everyone seems to go for the cyans (or turquoise).

    My understanding of photoptic vs scotoptic vision is that a bright light while in scotoptic, will put you right back into photoptic mode. So, you have a flashlight optomized for your night vision, but as soon as you turn this bright light on, your night vision goes away and the flashlight is no longer optomized. Is my reasoning flawed?? I can understand the whole deal with using a cyan at extremely low power as the perfect night vision retainer light but as soon as you increase power, that ability goes away.

    Comments?

    Mark

  6. #6
    *Flashaholic* McGizmo's Avatar
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    Default Re: Inretech 2AA Cyan?

    Mark,

    I certainly don't pretend to understand the physiology or physics involved but I think most important is the relative levels of light at hand. In my way of thinking, night vision is obtained when your eyes have adapted to low levels of light. The more equal in relative brightness your surrounds, the easier it is to make out the picture. If it is too dark for the eyes to register, then enhancing the area with some additional light is required. I suspect that even more important than the wave length is the added level of light brought forth. I am led to understand that it takes less illumination in the red spectrum because we have more rods to pick up this light. However you need to look a bit askance for the rods to catch the light. Lately, the green or cyans have been championed for night vision as I suppose these colors are the easiest for the cones to detect?

    Either way, as you have alluded to, if you dump too much light, regardless of the wave length or if it is full spectrum, night vision is compromised and areas of shadow are indeed in shadow. When I first encountered the super bright white LED's (Nichia and not the Luxeons) I realized that with proper placement and numbers of these, moonlight could be simulated and you could see the night instead of blasting it away; creating shadows and dependance on the light. I think a monochromatic selection of a wave length may be a method of fine tuning but if you "crank" the volume, as you have stated, it's a mute point! Too much light is easily the bane to seeing at night.

    Mike,

    I found the spectrum you posted above to be enlightening but ultimately misleading as we are discussing cyan here. I certainly have some LED's that emit the color you have identified with your spectrum image but as I asked above, I was curious as to which side of green cyan actually falls; my understanding that it was in the transisition from blue to green and not as your image depicts. Perhaps the human eyes do peak at the green/ yellow range of the spectrum. After reviewing the Lumiled spec sheet, I feel re affirmed in my understanding that cyan is on the other side of green. Lumiled cites the range for their cyan as being from 490 to 505 nm and green to be from 520 to 530. Nice graphic but you had confused the issue for me :-)

    - Don

  7. #7

    Default Re: Inretech 2AA Cyan?

    Firstly, LEDs are still a far cry from even a modest incandesent bulb, especially in the domain of "throwing" distance.

    Now, I don't own a 1w cyan luxeon light, but I do own a 5w Cyan and a couple of cyan nichias, so I can speak to the usability of the light.

    Answer: excellent, unless (and pardon me from pointing out the obvious) you want a white light, to which cyan is a very poor alternative.

    It is however brighter than a white LED - because there is no light being wasted by a phosphor, and because our eyes are "tuned" more to the green portion of the spectrum. They might also run at higher current than the white (actually blue, but I digress) ones, I honestly don't know. Cyan is better for preserving night vision, too.

    For what you want the light to do, I'd imagine the InReTech would be just fine

    --Scrimmy

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    Default Re: Inretech 2AA Cyan?

    Yes, you are both correct - the Cyan will "appear" to be the "brightest" of all the colors due to the sensitivity of the human eye at that frequency

    Although, using a non-white light source will make what you are trying to look at not render properly

    http://www.inretech.com/pictures/response.jpg

    Mike
    www.inretech.com

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    Default Re: Inretech 2AA Cyan?

    I always thought that Cyan was Blue/Green also, but again - each company uses the colors differently

    The Wavelength is more precise

    We will be updating the screen shot on our home page with the two new colors (Cyan and Amber) as soon as we can

    Mike
    www.inretech.com

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    Default Re: Inretech 2AA Cyan?

    I understood cyan to be a colour whose wavelength is about 555nm. I've certainly found that LED torches using this wavelength are very effective and is one reason why I can sell many more cyans than the other colours. White LED's are an improvement on the yucky yellowish-white emitted from filament bulbs, but in a hand held torch I truly find Cyan easy on the eyes. Green is also very good, particularly in a camping torch (most of the vegetation is green and will readily reflect green light.) Blue LED's can be quite effective as a map reading light, but its throw is not as effective unless you go for a narrow beam LED.

  11. #11
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    Default Re: Inretech 2AA Cyan?

    Nope...don't know why you guys are getting cyan mixed up with green...

    http://www.nichia.co.jp/product/lamp-color.html

    Nichia sells the blue-green (cyan) LEDs as being 505nm and its greens are 520nm.

    Lumileds sells its Luxeon Stars in Cyan as 505nm and Green as 530nm.

    Below 505nm is less cyan and more blue and above 530nm is less green and more yellow.

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

    http://www.psychology.psych.ndsu.nodak .edu/mccourt/website/htdocs/HomePage/Psy460/Sensitivity%20Regulation/sensitivity%20regulation.html

    Mark

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    *Flashaholic* McGizmo's Avatar
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    Default Re: Inretech 2AA Cyan?

    Minjin,

    Facinating links! Thanks.

    - Don

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