ReviewTheLight: Nitecore P20UV (800 White Lumens + 320mw of 365nm Ultraviolet)

[TheVisitor]

Thanks for the review - helped me to decide the torch is for me and purchase. Thanks

 

[Bigmac_79]

Thanks for the review - helped me to decide the torch is for me and purchase. Thanks

Glad it was helpful!

 

[NoNotAgain]

Bigmac 79,

How bright would you judge the UV portion of this light to be? I also own the P20UV and am disappointed with the UV brightness. My Led Lenser V2UV using only 3 leds is much brighter than the Nitecore P20UV.

I typically use the UV for finding places that the cat yacked something up and the Nitecore isn't cutting it.

 

[y260]

Bigmac 79,

How bright would you judge the UV portion of this light to be? I also own the P20UV and am disappointed with the UV brightness. My Led Lenser V2UV using only 3 leds is much brighter than the Nitecore P20UV.

I typically use the UV for finding places that the cat yacked something up and the Nitecore isn't cutting it.

If your lenser seems much brighter, that could indicate a shift towards the visible spectrum, which may light up more of a room, but isn't "true" UV. I find the P20UV to be moderately powerful and perfect for close-range UV stuffs. Like finding marks on currency or on a passport, etc.

 

[Bigmac_79]

Bigmac 79,

How bright would you judge the UV portion of this light to be? I also own the P20UV and am disappointed with the UV brightness. My Led Lenser V2UV using only 3 leds is much brighter than the Nitecore P20UV.

I typically use the UV for finding places that the cat yacked something up and the Nitecore isn't cutting it.

It's hard to say how bright it is, as lumens are really only for visible light. Nitecore claims 320mW for the UV power here, and I have no reason not to believe them. If this isn't enough power, they also have the CU6, which I haven't reviewed, but claims 3000mW.

However, though the power certainly matters, when it comes to using a UV light the actual wavelength of the UV is very important. With visible light you're just bouncing light off stuff so all you need to do to see it better is add more light. With UV, you're trying to get the light absorbed by an object so that it will re-emit light of it's own, and it's that light you see, so what you really need to do is hit the right wavelength. For whatever reasons, most UV lights either claim to be 365nm or 395nm. I haven't done enough research on them to know much about the spread, but you can see the P20UV seems to peak pretty close to 365 as claimed (see spectrum in the review). 365nm UV is further from the visible spectrum, so even if it is a very powerful light, you won't see much of the actual UV light, just mainly the light from the fluorescing objects. 395nm UV is closer to the visible spectrum, so a less powerful light can still appear to be fairly bright. Also, 365nm will generally look more whitish, where 395nm tends to look more like a deep purple. So which is better? It depends on what material you want to see. A while back I found a chart that showed when wavelength various materials reacted best too, but unfortunately I didn't bookmark it. The little presents your cat leaves may fluoresce better at one frequency than the other, so you need to decide which one. Also, because the 365nm light is less visible, it tends to make fluorescing objects stand out in the apparent dimness of the beam.

If your lenser seems much brighter, that could indicate a shift towards the visible spectrum, which may light up more of a room, but isn't "true" UV. I find the P20UV to be moderately powerful and perfect for close-range UV stuffs. Like finding marks on currency or on a passport, etc.

Yeah, I don't know what the wavelength of your led lenser's UV is, but in general it seems most of led lensers lights are fairly under-powered, so I would guess it's a 395nm, which would explain why it appears brighter.

 

[NoNotAgain]

If your lenser seems much brighter, that could indicate a shift towards the visible spectrum, which may light up more of a room, but isn't "true" UV. I find the P20UV to be moderately powerful and perfect for close-range UV stuffs. Like finding marks on currency or on a passport, etc.

I'm using the light in almost total darkness. There's a throw comforter on the sofa which strangely has a number of blocks which fluoresce quite brightly.The Nitecore P20UV doesn't light up the comforter like the Led Lenser. The same thing for the lumensiant dial on my watch.

Finding cat yack is much easier after you hear them go than waiting for the morning and then having to scrub the hardwood floor and re-oil.

I've got a lab grade UV / black light, but it's got to be plugged in making it a pain to use.

 

[Bigmac_79]

I'm using the light in almost total darkness. There's a throw comforter on the sofa which strangely has a number of blocks which fluoresce quite brightly.The Nitecore P20UV doesn't light up the comforter like the Led Lenser. The same thing for the lumensiant dial on my watch.

Finding cat yack is much easier after you hear them go than waiting for the morning and then having to scrub the hardwood floor and re-oil.

I've got a lab grade UV / black light, but it's got to be plugged in making it a pain to use.

Do you still have the manual or box for your V2UV? I tried to look it up but just found this: http://www.amazon.com/dp/B00097A7NE/?tag=cpf0b6-20. If you have the box or manual it might say the power in mW or the frequency in nm. The two most likely reasons for the V2UV to perform better at those tasks are either that it has a better frequency for those materials, has a higher power output, or both.

 

[NoNotAgain]

I've got the box, but don't recall them having a manual inside. I've checked all three boxes and they're all the same, no manuals.

The only thing I can add is that there is a sticker inside the box indicating Nichia LED's were used. I looked up Nichia UV led's and the only unit matching the packaging is the NSPU510CS. The charts appear to suggest that the led operates between 365-370nm at a power rating of 15.3mw .

The model light number is/was 7732DUV

Coast list the model as PX10, but not information on the UV capabilities.

 

[Bigmac_79]

I've got the box, but don't recall them having a manual inside. I've checked all three boxes and they're all the same, no manuals.

The only thing I can add is that there is a sticker inside the box indicating Nichia LED's were used. I looked up Nichia UV led's and the only unit matching the packaging is the NSPU510CS. The charts appear to suggest that the led operates between 365-370nm at a power rating of 15.3mw .

The model light number is/was 7732DUV

Coast list the model as PX10, but not information on the UV capabilities.

That's interesting, it looks like it's got the same wavelength, and 6 emitters with 15 mW each is only 90 mW. I guess I can't say why your V2UV seems better at finding the cat's stains :shrug:

 

[Tenryu137]

Hello Bigmac, great review :twothumbs
i'm new to this flashlight world and the only flashlight i owned is a cheap 10 dollar plastic

Do you think P20UV is a good choice for a newbie like me? I need it for everyday carry and i just got an ESP LHU 14-35 holster from my friend....

 

[seong87]

Just brought the p20uv.great light but i notice the four uv emitter has 3were white and 1 purple when pointed to the wall at close distance.is that same with the p20uv everybody has purchase?THANKS.