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Thread: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

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    Default 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    I've been a lurker at CandlePowerForums for a while - some great info here - thanks!

    So I recently had cataract surgery - at age 48, it was a few decades early ... but all went well. To make a long story short, I can now see in the UV spectrum - even got tested on a Monochromator at HP Labs - click here for my lengthy writeup with pictures and analysis about seeing Ultra-violet after cataract surgery.

    So after playing around with a GE F15T8/BLB Black Light, I wanted to get a UV flashlight for more portability ... but wanted something at a low wavelength ... and ended up getting this Gallion Indium Nitride 365nm 9 LED flashlight from Amazon. I also got an el-cheapo 400nm UV flashlight - same form factor, but spills much more light into the visible regime.

    It's pretty easy for me to test these (since I can see UV! ;-) as I simply compare what I see with/without a UV filter or polycarbonate safety glasses. Not much difference on the el-cheapo 400nm light ... but a significant difference with the 365nm light.

    But the 365nm still "spills" a bit of light into the visible spectrum. I.e. I can see some light even through the UV filter. I'm wondering if perhaps the plastic cover (over the LED's) is causing this? I have tried to remove it, but even with pliers, it doesn't seem like that top will unthread.

    This is a bit frustrating since it defeats the purpose of a 365nm flashlight ... and in this CandleForumPower thread, it seems other people have noticed this ... with one suggestion being to replace that plastic cover with Woods Glass.

    Curious if anyone else has experience with these flashlights and any other suggestions on how to minimize the emission in the visible spectrum?

    Thanks,
    alek

  2. #2
    Retired Administrator Norm's Avatar
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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    Alek

    I had cataract surgery in 1997 at a similar age 44 due to side effects of medication, I read the linked article but I've never experienced any of the changes mentioned in the article.

    I have a nice custom Peak LED Solutions 375nm flashlight and a flourescent UV unsure of the frequency (guessing 365nm).

    No super powers using either light.

    Norm

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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    Welcome to CPF, alek

    That's amazing - I never heard of anyone before who could see in the UV spectrum. Many animals (deer etc) can see UV, but you're the first human I've heard of (other than Norm, of course - don't believe his denial there, he has POWERRR, lol)

    I just posted here about UV wavelengths, although I don't think that helps much with what you are asking. We've had lots of threads on UV in the past, and I'm sure other members will chime in.
    Resistance is futile...

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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    I wish i could help you with the issue. Ive never had eye surgery but i can definatly see more into the UV spectrum than anyone i know. standard blacklights like you have in the writeup make my eyes burn, even with short exposure, for a couple hours. I need to use to UV glasses around any potential UV light sources other than being in daylight.

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    Flashaholic* derfyled's Avatar
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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)



    I can't help with the specific question but thanks for bringing this strange phenomenon, very interesting.
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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    Maybe search after a UV light with "woods glass", that is supposed to block visible light.
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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    That is amazing, I know that you can purchase UV LEDs (they are used in sensor bars for nintendo wii) you might be able to build some sort of torch yourself using these, that would be pretty awesome to go into caves or something with it and be the only one able to see... Did some reading and you are quite lucky, only two other people in the world (according to wikipedia) have been tested and verified as a tetrachromat.

  8. #8

    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    i have few 360nm uv leds i too see the weak visible light emmited by them.
    few times i had to use some eye drops that made me see a lot better in the dark, there was ancient mostly cave dwelling civilisation in peru iirc that used drugs which had the same effect but stronger, they could see in dark caves with no fire or any light source.
    Last edited by alpg88; 03-10-2015 at 07:29 AM.

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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    WOW! You have super powers!

    I wish I could see the infra-red spectrum, so I have night vision . No more need for red filters!

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    Flashaholic* firelord777's Avatar
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    Wow! I wish I could see UV as well! So many things you could do...

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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    Well I think a lot of people can see the light emitted by a UV light, but an IR light is a different story, can you see IR light? I have a UV flashlight and I can see the light if I shine it at the ground, but an IR flashlight I cannot. The only way I can see the IR light is if I use a camera.
    Last edited by my#1hobby; 12-09-2011 at 02:52 PM.
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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    I read your article on your post-cataract surgery experience and found it very interesting.

    I had cataract surgery many years ago and am aphakic. Like you, I can see well into the UV spectrum. How far, exactly, I don't know.

    But being able to see UV means that a good deal more of that shorter wavelength light is reaching your retinas, which is basically really, really, bad.
    Last edited by BigBluefish; 12-09-2011 at 05:42 PM.
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    Flashaholic* derfyled's Avatar
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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    Quote Originally Posted by cbutters View Post
    tetrachromat.
    What a nice word
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    Quote Originally Posted by derfyled View Post
    What a nice word
    Word of the day ladies and gentlemen

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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    FYI that a "tetrachromat" is someone who has 4 color channels - Wikipedia reference - which gives you much broader color discrimination - I don't have that ... and from what I understand, it only happens in women anyway.

    My situation is similar to BigBluefish'es - it's the ability to see below 400nm in the spectrum.

    Back to my original question, I guess what I'm wondering if I had a "bare" 365nm LED, would it emit much visible light? I.e. is what I'm seeing from this specific flashlight actually coming from the LED ... or re-transmission into the visible from the plastic cover?

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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    You should be interested in this article then - http://neuronresearch.net/vision/fil...topiceffic.htm

    "The common wisdom has been that the human eye has no ultraviolet sensitivity and that its response to ultraviolet light was due to fluorescence within the eye. This is clearly not the case."

  17. #17

    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    Quote Originally Posted by alek View Post
    Back to my original question, I guess what I'm wondering if I had a "bare" 365nm LED, would it emit much visible light? I.e. is what I'm seeing from this specific flashlight actually coming from the LED ... or re-transmission into the visible from the plastic cover?
    Maybe not the best method, but this is all I can think of if you can't remove the lens:

    Any photons coming out of the lens instead of the LED will be on random paths, not the original paths of the photons from the LED. So, any light emitted from the lens would be very floody, it's beam profile would be out beyond that of the light coming from the LED. So what you might be able to do is shine the light on a white piece of paper (or any uniform florescent surface) at very close range, and take a look at the paper. Any non-UV light light will fail to make the paper floresce. Combine that with the fact that it would be floodier, and if it exists, you should see a bit of light at the edge of the main part of the beam that is very dim (or possibly bright if there is a lot of light being absorbed and re-emitted by your lens) and does not make the paper floresce.

    Of course, this is just speculation. I tried it with my UV light, and didn't see anything, so either my lens is perfect or my idea is off-base

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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    Quote Originally Posted by alek View Post
    . . . My situation is similar to BigBluefish'es - it's the ability to see below 400nm in the spectrum. . . . .
    Some people who can see <400nm see it as white rather than purple. I'm pretty sure it's mentioned in Fulton's work.
    http://www.neuronresearch.net/vision...formance1a.pdf

  19. #19

    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    Quote Originally Posted by MikeAusC View Post
    Some people who can see <400nm see it as white rather than purple. I'm pretty sure it's mentioned in Fulton's work.
    http://www.neuronresearch.net/vision...formance1a.pdf
    Mike,

    I quicky reviewed some of Fulton's work. Most interesting. There is quite a bit of discussion of UV sensitivity, so it's going to take me a while to go through it.

    For me at least, the emissions for UV sources are distinctly purple. Ultraviolet lamps used for mineralogical displays, and those used in the food service industry (I believe to kill bacteria or viruses) give off a very obvious glow, and bathe the surrounding surfaces with a deep to medium purple, or light purplish-blue hue when viewed without looking through plastic or polycarbonate lenses, which both filter out some UV. Like the OP, I have also noticed on several occasions that certain fabrics (or more likely the dyes used in them) appear to reflect light in the UV range. What appears black or gray when viewed by me through polycarbonate prescription lenes, and when viewed by other non-aphakic individuals, appear distinctly violet, or even light-purple, when I view them without using glasses.

    As to the OP's question, I believe another poster just started a thread regarding Woods Glass and 365 nm UV emitters. http://www.candlepowerforums.com/vb/...r-for-UV-light. Oops, not a new thread, just newly bumped by response, so perhaps, OP, you have already seen this.
    Last edited by BigBluefish; 12-11-2011 at 07:26 AM.
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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    Hello, it's very interesting to read about your ability to see in the UV - although I would be careful, as I don't know the response of the retina, but you may get getting a lot of UV in to see it, and they're very high energy photons, may not be good for the retina (the lens/cornea blocks the UV for most people).

    If you want to eliminate any fluorescence and maximize the output from the device, then fused silica would work well, it transmits in the UV spectrum, where as most plastics/glasses block it.

    You will probably struggle to eliminate all light from the visible spectrum, as the UV will fluoresce many materials, again due to the high photon energy. I have a 405nm laser pen (lower photon energy than 365), and although that's in the visible spectrum, very deep violet, it will fluoresce many materials to a bright blue, having said that it's a much more focussed beam.

    Hope you eventually find your invisible torch, and perform the deeds you intend to with it !

    Edit: Here are the spectrums for Wood's glass and fused silica, although fused silica is transparent in the visible, the visible light shouldn't exist as it transmits 90%, this means that very little is absorbed so shouldn't fluoresce.

    Wood's glass does fluoresce and produce visible light, we know that as everyone can see when a blacklight is on or off.

    Fused silica:



    Woods glass:

    Last edited by Tsportmat; 12-11-2011 at 08:00 AM.

  21. #21

    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    Quote Originally Posted by MikeAusC View Post
    Some people who can see <400nm see it as white rather than purple. I'm pretty sure it's mentioned in Fulton's work.
    http://www.neuronresearch.net/vision...formance1a.pdf
    WOW ... that is quite the writeup!!!

    And yes, discusses a fair amount about UV "seeability" that I've seen in my misc. research.

    Ditto what BigBluefish said (again) as my experiences are very similar.

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    Flashaholic* firelord777's Avatar
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    I think it could be an advantage in an stealth ops mission? Only you could light up targets without actually lighting them LOL

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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    I've been thinking about this, and obviously alek must be a superior being, a sort of real-life X-man.

    Think about the advantage he has over most people - for a start, he will see all scorpions lit up like beacons and will easily be able to avoid stepping on them.

    I think he may have to be assimilated...

    LOL
    Last edited by DM51; 01-02-2012 at 10:53 AM. Reason: add link
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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    Like the OP I've been a lurker at CandlePowerForums for a while.

    I haven't yet began my slew of questions upon you guru's as I haven't had the time yet, but it's coming!

    Anyway I found this thread VERY INTERESTING! and wanted to put my 2 cents in...

    First to your solution, Wood's glass is the best known filter for blocking visible light and not UV/IR, however even being the best it does not block "all" visible light. IMO the only way to accurately test your capabilities is with lasers.
    Artificially, UV light is usually produced with mercury-vapor, deuterium lamps, and with LED's a slew of chemicals/elements even some Deep-UV wavelengths were obtained in laboratories using aluminium nitride (210 nm), boron nitride (215 nm) and diamond (235 nm). (Wiki) The trouble is that these lamps also produce a certain visible light content. So when you turn them on they glow visibly. "one can make 'pure' UV of a single wavelength using a laser. Usually a frequency-doubled argon gas is used to produce a continuous wave beam of UV light. This beam, say at 244 nm or 300 nm, can not be seen at all with a human eye.
    However if you put a piece of paper in its path the paper will glow blue. This happens because the UV excites blue dyes in the paper (the paper manufacturers put blue dyes in all papers to make them appear more 'white')." Anton Skorucak, M.S. Physics I guess bottom line is that in order to see no visible and only UV you would have to make a laser for that nm specification. It would be cool to know exactly how far into the UV spectrum you can see, if that is what is happening.

    ​I would think then if you were capable seeing such wavelengths by creating such beams, that you would be able to actually see the beam itself not its reflection on the paper. I seriously doubt that you could do that. Alternatively what I do think is happening is a filter effect of sorts. "
    By definition, ultraviolet light is 'beyond violet light' and the visible spectrum that can be detected by the human eye. It cannot, therefore, be seen directly. Detectors that are sensitive to UV convert it into a form that we can see. Technically, you can 'see' the UV part of the electromagnetic spectrum if you and the source of UV radiation are receding from each other at a high enough velocity to red-shift high frequency UV waves into the visible spectrum. In this scenario, however, UV light is being emitted, not received. Anton Skorucak, M.S. Physics. MikeAusC Posted this link above http://neuronresearch.net/vision/fil...topiceffic.htm which does support the idea that we can see outside of the "norm", perhaps with a little coaxing. It is my understanding that what this article discusses is pointing in the wrong direction.

    Let me explain with an example. Neon Oxides (powder) in a jar is VERY BRIGHT, however in very small amounts are invisible to the naked eye. I have coated a piece of Styrofoam with this powder and then washed it off with soap and water. To the naked eye it appears all white. When I use my JetBeam BC25 with the blue filter, I am guessing around ~405nm some of these particles become visible, When I add ~580nm (Yellow) goggles even more of these particles become visible. (Putting the yellow over the blue lens does not have this effect, it is within the eye itself and the perceived light activated by the fluorescent. When using my Woods Glass Fluorescent tube, ~368 to 371 nm I can see even more particles but with the same goggles there is no improvement at this wavelength (I simply don't see blue neon). So with lights closer to the visible spectrum the goggles lens actually makes things visible that wouldn't be unless you have a light of a lower wavelength. We must first establish that UV light is not visible until it has activated the phosphorous compound, and then it is not the UV light that we are seeing but the activated phosphorous color. (i.e. the paper and the uv laser) You cannot see any light from behind the source, it is the reflections off of the particles (in the air on the wall, etc.) that are beamed back to our eyes. I bring this up because in your pictures you show that you can see the reflection off the wall wider than us, you don't seem to mention that the beam is wider to you.

    My point here is that I don't think that your eyes can see UV light in the form of omitted power. I do think that your eyes may have new filter that allows you to see what is typically unseen. Kind of like my yellow glasses with my blue led. This is the activated, or perceived light that I believe you are seeing. (Esp. paint on the wall clothing, paper, etc.) Theoretically that would also mean that you have now lost or diminished the ability to see the opposite of the spectrum...theoretically. Much like my yellow glasses I don't lose any real significant brightness. Under blue light, in fact it is perceived as brighter being closer to green/yellow, but under white light I can't discern yellow but Blue things really stand out, they are much darker!

    So I have a few questions...

    1. Have you taken a Ishihara Test since the surgery?

    2. Do the colors green and red sometimes appear brown to you?

    3. Have you tried using High near UV (420-395nm) light on fluorescent inks or dyes (like in money), if so are you able to depict the color of the stripe?

    4 Using UV absorbent material, beaming your UV flashlight at it, can you still see the wider reflection?

    5. How about the beam itself in a smoky/foggy room, compared to others without the surgery?

  25. #25

    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    Quote Originally Posted by alpg88 View Post
    i have few 360nm uv leds i too see the weak visible light emmited by them.
    few times i had to use some eye drops that made me see a lot better in the dark, there was ancient mostly cave dwelling civilisation in pery iirc that used drugs which had the same effect but stronger, they could see in dark caves with no fire or any light source.
    steroids, dilated your pupils

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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    Quote Originally Posted by cbutters View Post
    That is amazing, I know that you can purchase UV LEDs (they are used in sensor bars for nintendo wii) you might be able to build some sort of torch yourself using these, that would be pretty awesome to go into caves or something with it and be the only one able to see... Did some reading and you are quite lucky, only two other people in the world (according to wikipedia) have been tested and verified as a tetrachromat.
    I don't think seeing UV in this manner is tetrachromatic vision. I think those people have four groups of cones. Since his power has something to do with changes occurring in his lens, I don't think he has developed a separate cone group during adulthood. Genetically, it is HIGHLY unlikely for a male to be tetrachromatic. It is hypothetically possible for a female to have a mosaic expression of four cones in the retina, but this has never officially verified with a real human, I don't think.

    And none of these scenarios would not result in tetrachromacy like that found in birds, for example. That's really four cones, one centered in the UV range.

    That is likely just what Wikipedia would say.

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    Flashaholic* hank's Avatar
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    Default Re: 365nm UV Flashlight ... since I can actually see that wavelength! ;-)

    I've got the same situation in one eye -- cataract surgery and replacement lens back in the years before they added UV filtering to the IOL implant material.
    So I can compare the operated eye with my normal aged lens in the other eye.

    With a UV flashlight, I see almost nothing with the normal eye (remembering it's an aged, yellowed lens)
    and with the operated eye I see a nice bright violet illumination.

    I've been cautioned all along to be _very_ careful about wearing UV-blocking lenses outdoors, preferably blue-blockers as well, because the operated eye lacks the natural protection that the normal lens gets increasingly as it gets yellower with age.

    This by the way is also the explanation for younger people seeing "blue hair" from hair salons for older women -- with yellowed natural lenses ordinary white looks grayish, so salons add an optical brightener that fluoresces to the hair rinse -- and to the customers it looks bright white as they want.

    It's not 'tetrachromaticity' -- it's just that the human retina does detect photons in what we call the UV range if it's not protected by the natural lens.

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