Need UV light fr footbag/hackey sack night - glow within 10ft, dangers? OtherOptions?

So I enjoy the sport of footbag/hackey-sack. The art of juggling a ball with your feet alone, and kicking it around in an attempt to perform skillful maneuvers and tricks. Successfully doing so causes me great joy and is a wonderful form of excercise, and a very social sport with friends of any skill level.

I always EDC a flashlight, a footbag, a multitool, etc, etc. My problem has been attempting to play with a friend (or solo) outdoors at night time. Parking lot street lamps are not really bright enough usually. Store front lights are not the best nor are they very appropriate as they disturb the peace. My EDC light is insufficient, it works only on max turbo mode (Zebralight SC63NW @ 1150 lumens) is great.... for about 15 seconds when it overheats. I need the light for 30-120 minutes at a time. I've considered many different LED lightning options, and have even tried regular glow-in-the-dark footbags. Generally you have to hold a flashlight to the light-activated footbag for a few seconds, and the after glow fades within a mere 1-3 minutes. This is hardly practical and puts a hold on the fun. There are also footbags which exist that contain LED lights within the actual ball, however the quality of play due to the feel of the footbag is decreased greatly. I've considered EDC lamps of all sorts, even small lanterns (by the likes of Nitecore especially) but they are simply not bright enough. At night time, when under a street lamp or some light emitting a few thousand lumens, adding a couple hundred more in a non-focused pattern (which it must be - since kicking it can land it anywhere within 10 feet) is pretty unnoticeable and doesn't help at all.

Therefore, I've come across another option. An EDC UV light, with a UV activated footbag/hackey sack.




But how much UV light is necessary? Can it be EDC'd safely? And i mean 99.999% safely with essentially negligible health risks? I just want to illuminate a small 2 inch diameter ball within 10 feet at night time. Id prefer a small 14500 light with a pocket clip to attach to some clothing during play, or to place on the ground nearby, facing upwards towards my friend and I to light up the ball well. 18650 will work if its super ultra compact, like the SC63 size that i currently EDC.

Other options include this glow-in-the-dark paint spray can that I have, I could spray it on a ball but i imagine it wouldnt work any better than the first ball which already contains the same chemical to make things glow after being lit up by normal wavelengths.

Any recommendations or new ideas are greatly appreciated!

Get a bag and test. You will probably find that the UV activated bag will glow best in areas with low ambient light. The safety of UV is tied to wavelength, do some research and buy appropriately, there's a huge amount of cheap flashlights available with lots of different emitters. But you may not need UV, the old royal blue Luxeons did a pretty good job making "day-glo" stuff light up and the light would carry farther than UV

I am still on my search for a UV light for hackey sack, since I have 3 fluorescent colored footbags coming in the mail.

What wavelengths are best on flouescent neon / orange / higher lighter colors to produce the most glow?

Will be posting here quite a bit until I find an answer... pretty deep into the search now, spent 2 hours watching videos about UV lighting but I am still quite confused, sadly.

Have you checked Nitecore. They have a couple UV lights in their GEM line, and one I think should be bright enough for you. I also noticed today that the Sofirn Store at AliExpress has a 365nm UV light that runs off of an 18650.

The big problem is that UV light, especially at 365nm, can damage one's eyes. I am afraid that having a UV light bright enough to make your ball glow would be bright enough to damage your vision if it happened to shine in your eyes. One thought would be to go to NiteIze and get their elastic headband that can be used to mount a normal light as a head lamp. That would definitely keep the light out of your eyes.

You may not need UV. The "electric yellow" may glow well enough under blue light. The blue would be less damaging to the eyes and you should be able to find higher output with a blue LED light. You can get blue and UV coin cell key chain lights cheap to test the effects up close and then search for a brighter light based on your comparison.

Timothybil said:

Have you checked Nitecore. They have a couple UV lights in their GEM line, and one I think should be bright enough for you. I also noticed today that the Sofirn Store at AliExpress has a 365nm UV light that runs off of an 18650.

The big problem is that UV light, especially at 365nm, can damage one's eyes. I am afraid that having a UV light bright enough to make your ball glow would be bright enough to damage your vision if it happened to shine in your eyes. One thought would be to go to NiteIze and get their elastic headband that can be used to mount a normal light as a head lamp. That would definitely keep the light out of your eyes.

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Thank very much for your input.

Problem with a regular headlamp is a useful level needs about 700 lumens of mule-like flood since you are actively spinning your head / twisting body, and it absolutely blinds your partner that you are kicking the ball to, so a bright regular headlamp does not work very well. I thought about a lantern being placed on the ground between my partner and I, but I'm afraid of kicking / stepping on it, or if it's constant glowy glare would be an issue. Also it would need to be 1000 lumens output to emit enough light for a 10 or 15 foot area to see a small ball well. (Basically not pocket friendly anymore, 1k lumens continuous for an hour or two is rough, even on a 26650.) This is why I was going for UV... far less output needed, therefore smaller size, and only need the ball to glow, not the surrounding area....

I am considering two options:

1) Glow in the dark hackey sack, which is made from material that is actually activated by the light and remains glowy for 60-120 seconds with a typical flashlight being held against it at 1k lumens and then turned off. This solution would be to purchase a UV light like the Nitecore Tube UV or Convoy S2 365nm, and HOLD the light against the ball, while looking the opposite direction (although my hands would unintentionally get in front of the beam from point blank as I spin the ball in a circle to light all sides until it is fully glowing before turning it off.) My question is, can staring at the glowing ball emit UV damage too? Since the UV particles are like transferred into the fabric if I read correctly? And how much longer would the ball glow over a typical white flashlight at 1k lumens? I was hoping it would be activated like 3-4x stronger and last 5 minutes per charge. Then I could just quickly recharge it with the UV light at point blank (but possibly damaging my hands while lighting it up every 5 mins for 10 second intervals)


2) 395-450nm weak UVA/blue light that would HOPEFULLY keep a flourescent colored fabric lit, and it wouldn't damage my eyes or skin because of the longer wavelength, right? But it would have to stay on the entire time, no after glow for the fluorescent colored hackey sack. Meaning bigger light needed, in a floody beam pattern. And possibly 2 lights, one for me and one for my partner who will be standing opposite of the ball, thus my light won't hit his side of the ball to see.


Which seems more logical / safe / effective?

ZMZ67 said:

You may not need UV. The "electric yellow" may glow well enough under blue light. The blue would be less damaging to the eyes and you should be able to find higher output with a blue LED light. You can get blue and UV coin cell key chain lights cheap to test the effects up close and then search for a brighter light based on your comparison.

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Perfect! This is what I was hoping someone would say. You typed this as I was writing my previous post, thanks... I appreciate the test cheap key chain light idea. What wavelengths nm would work best do you think? 405? 420? 450? 500?

Blue starts around 450nm according to what I read,below that is purple/UV. Probably want to be around that wavelength as the other end of the blue spectrum meets up with cyan. Cyan will not work for your purpose as it doesn't make items "glow". Not sure if blue can cause eye damage like UV though I doubt prolonged use of blue is particularly good for your vision.

I like what you are trying to do but I am skeptical it will work. If there is too much ambient light it will interfere with the effect and if you go to a darkened area I am not sure you can generate effective flood with a single light outdoors. It seems like overhead blue area lighting is what you would need but that is not possible outdoors. Maybe if each person playing has a blue light you can make it work.Interested to know what you come up with either way

Blue light would probably be distracting. UV would work, but I think it would need to be brighter/floodier than a flashlight will provide. Something like a mounted UV tube light is the way to go, but obviously it won't work in your application.

If you go UV, don't position the light so it shines in your eyes. Instead, position it up high, and aim it downwards toward your play area. That way, it will stay out of your eyes.

Convoy makes a nice 365nm UV light in their S2+ host. It might be bright enough, but I'm not sure if the beam will be wide enough to light up the sack wherever it goes. But for around $20, it's worth a try.

Thank you all... I'll look into 450-480nm blue light sources then, great.

But yes, it will certainly be prolonged use. Sadly I can't position the light above me, we play in random public areas like sidewalks, store fronts/sides, parking lots, front yards at night. Often times, the parking lot lights are too dim even when standing directly under them. Same goes with home porch flood lights, and store perimeters.

We could possibly do 2 tailstanding 21700 white headlamps on ground from opposite sides facing towards the center play area at continual 500-700 lumens. Thoughts? $ tho. Lots to carry if I must provide both lights too.

Comments on typical glow in the dark material hackeysack (not fluorescent) + 365m UV purely to charge it up for longer than a white light would provide? Can anyone testify to the % increase in duration / glow compared to a typical point blank flashlight blast? I could carry a small reflective bag for the GITD hackey sack to shine the UV light INTO while shaking around so the UV doesn't damage my skin/eyes when I'm charging the light. (Unless it penetrates the bag material?) This seems most practical but no one has been able to tell me how much longer the UV will make GITD stuff glow compared to regular light charge ups, which are very weak/short lived.

So far we've theoretically established:

1. Continual steady fluorescence using a flashlight is unlikely to work, as there is too much ambient light outdoors, no constant place to mount above and would probably need 1 light per person, head mounted, meaning 450-500nm light WILL shine into each other's eyes from 3-8 feet continually for 2 hours. Only other way is a ground tail standing light flooding into our eyes and the hackey sack. Debatably even worse...

2. A regular white light is too big/heavy to EDC to run 1k+ lumens flooded for 1-2 hours without overheating. That would need a 3x or 4x18650 light, not pocket friendly.

3. Two mounted headlamps in general will blind each other, so that's no good either.

OnlyownEnergizer250lumen said:

Comments on typical glow in the dark material hackeysack (not fluorescent) + 365m UV purely to charge it up for longer than a white light would provide? Can anyone testify to the % increase in duration / glow compared to a typical point blank flashlight blast? I could carry a small reflective bag for the GITD hackey sack to shine the UV light INTO while shaking around so the UV doesn't damage my skin/eyes when I'm charging the light. (Unless it penetrates the bag material?) This seems most practical but no one has been able to tell me how much longer the UV will make GITD stuff glow compared to regular light charge ups, which are very weak/short lived.

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I don't think a UV light will charge up your GITD material any better/longer/faster than a regular white light. The advantage of a UV light is that is won't wreck your night vision when charging up your balls.

Don't be too paranoid about UV exposure. It's not going to instantly blind you or anything. But, it's not good to point a UV light at your eyes, since that can cause damage especially over time. UV-C light is bad for your corneas even in brief doses (it will turn them into sandpaper for a few days), but you're not going to get that from a flashlight.

If you don't mind charging up your balls every few minutes, then a small UV light might be a good way to go. I'd skip the reflective bag, etc., and just use it like a normal flashlight.

WalkIntoTheLight said:

I don't think a UV light will charge up your GITD material any better/longer/faster than a regular white light. The advantage of a UV light is that is won't wreck your night vision when charging up your balls.

Don't be too paranoid about UV exposure. It's not going to instantly blind you or anything. But, it's not good to point a UV light at your eyes, since that can cause damage especially over time. UV-C light is bad for your corneas even in brief doses (it will turn them into sandpaper for a few days), but you're not going to get that from a flashlight.

If you don't mind charging up your balls every few minutes, then a small UV light might be a good way to go. I'd skip the reflective bag, etc., and just use it like a normal flashlight.

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I already EDC a 1-2k lumen light so no point in having a small UV light if you are certain that it won't charge the balls any longer/better/faster... are you sure? I read about people owning these collectible 'pops' characters and people recommended a UV light because the GITD material stored far more of the glowy photons power when charged with UV over regular lights... (sorry if terminology is off)

OnlyownEnergizer250lumen said:

I already EDC a 1-2k lumen light so no point in having a small UV light if you are certain that it won't charge the balls any longer/better/faster... are you sure? I read about people owning these collectible 'pops' characters and people recommended a UV light because the GITD material stored far more of the glowy photons power when charged with UV over regular lights... (sorry if terminology is off)

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I've tried it, and I didn't notice any difference. Maybe the UV charged it up a bit brighter for a few seconds? In any case, that advantage wouldn't give you more than a few seconds of extra time before it dimmed to the same level.

You don't need UV light to charge up GITD material. Blue light is fine, and white LEDs have plenty of blue spectrum in their light.

Thanks, I do trust your testing but am interested if others produced the same results. Which wavelength light did you use, and how much power was behind the wavelength? 500mW Or 3W? Big difference in output... and possibly big difference in 365nm vs some other UV length?

It's the phosphors that determine how quickly photons are released and thus how long the material glows. Different kinds of light won't affect how long the material glows, unless you can get it to glow more brightly in the first place and thus give it a bigger "charge". It will only glow longer for the amount of time it takes to dim from a "supercharge" down to a regular "charge". That isn't very long, from any GITD material I've seen, as it dims really quickly at first.

WalkIntoTheLight said:

It's the phosphors that determine how quickly photons are released and thus how long the material glows. Different kinds of light won't affect how long the material glows, unless you can get it to glow more brightly in the first place and thus give it a bigger "charge". It will only glow longer for the amount of time it takes to dim from a "supercharge" down to a regular "charge". That isn't very long, from any GITD material I've seen, as it dims really quickly at first.

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I see, so what if I spray or glue some extremely phosphorous material onto the hackey sack? Does such a thing exist safely and durably?

IMO UV light is a Bad Idea because
1. You already determined that you need very bright and very floody light. UV is not bright, and usually not floody either, so imo UV is not practical in terms of brightness and beam, to see a large area.

2. UV is dangerous.

IMO glow in the dark is not practical for the amount of play time you require.

and IMO, a sack with LED lights is probably the most practical option, in terms of the length of your sessions. Plus, it adds a whole new area of fun. You can Hack in full darkness, or dim light, no need to illuminate the area with a bright flood. And, it is very easy to find the LED Sack on the ground.

I vote LED Sack.

I'm heavily opposed to the LED sack because I expect a major downgrade in feel/control of the footbag. Nonetheless, I purchased one according to your suggestion last week Jon, and I am awaiting its arrival in the mail to experiment. They're also quite expensive, I had to pay $15 on sale (normally 20) for an item which has a non replaceable battery, a large obstructive clunky on-off switch on the exterior surface, and can easily be lost/damaged with use (holes form quickly in the fabric requiring replacement.)

I also play with many young people. I regularly give hackey sacks as gifts, and these would be especially desirable to newcomers for their novelty. If I give out 10... that's $150-200 instead of the 10 regular/fluorescent colored ones in the mail just purchased for $50.

If these LED sacks were $5-8 and maintained good control/feel, even with nonreplacable batteries, I think it would be okay... but we're talking 3x that.

OnlyownEnergizer250lumen said:

I see, so what if I spray or glue some extremely phosphorous material onto the hackey sack? Does such a thing exist safely and durably?

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Bump, still looking for an answer on this as a safe alternative/solution.

I agree there is no perfect sack to meet your specific needs.

That leaves you in a position to design one

There is also no perfect flashlight for all applications, which is why most of us own more than one.

I applaud your generosity in sharing Hacks with others, that is a very healthy habit.. I dont think anyone here has the answer to your needs and I agree that the LED Sack you ordered will not have an ideal feel.. Your design goals, and the use scenario you want to fulfill, are unique. I hope you come up with a great solution