good vs cheap UV?

[paulr]

I see Arc has now introduced an AAA model with a UV led, a nice one with 10 mw of output at 370nm.

Any idea how that output compares with the cheap coin cell UV lights like the one I got for $5 from Countycomm a few years ago? Obviously I'm very familiar with the difference between a top quality metal light and a cheapo coin light--I'm just asking about the output. I only occasionally have use for a UV light so I'm wondering what I'd be gaining by buying a good one.

 

[Norm]

The cheap coin cell UV lights I bought recently are rubbish mostly visibly light can't remember whether I bought the from Kai or DX. I'd say they were more of a purple light than a UV, any UV is washed out by the brightness of the visible light.
Norm

 

[Daekar]

There is actually a three-way comparison between two coin-cell lights and the new Arc-UV, and the Arc smashes the competition, hands down. Urine stain, currency, credit cards, ID, etc... it just did everything better.

 

[etc]

I got this 20LED uv light off ebay. Runs on 3AA, in 380nm. has no throw but flood.

 

[paulr]

Daekar, yes, I saw that mini shootout thread, but that was with shorter wavelength uv leds. I tested my cheap light last night and it shows the fluorescent strip in a $20 bill just fine, not blazing bright but certainly visible. I don't know the wavelength, maybe it's 410nm or something like that. I think for my current very limited purposes, my cheapie does the job, so I'll resist the temptation to buy the Arc, but will keep it in mind in case I decide I want a more serious UV light.

 

[LEDite]

Paulr;

I've built and sold a couple hundred UV lights over the last a couple of years.

I started with eight 5mm 395nm LEDs powered by a lithium ion 1350 mah battery.

Then I tried 20 to 50 of the 5mm 380nm LEDs powered by 1800 mah lithium batteries.

Next came the 1 watt Cree UV 395 nm LEDs with 2200 mah lithium batteries.

Now, I build Cree 3 watt 395 nm LED lights with aspherical lenses & 2400 mah Lithium batteries (Also in UltraFire C2 bodies).

Each light worked a little better for fluorescing the the common items such as urine, scorpions and UV dyes.

The 380 nm worked well, but didn't have the brute power that Flashaholics have come to enjoy.

The 3 watt UV Crees definitely perform the best in my testing for biological stains and routine fluorescence.

Larry Cobb

 

[xenopus]

Daekar, yes, I saw that mini shootout thread, but that was with shorter wavelength uv leds.

You will find you probably get what you pay for -- the new Nichia 375nm LEDs are great combining both shorter wavelength and power.

Piers!

 

[THE_dAY]

paulr, my guess is that you will be pleasantly surprised by the new Arc UV.
imo, it is amazing at flourescing objects compared to the other UV lights i've owned.
the Arc UV shootout i did was with lower wavelength LEDs but i've also owned higher wavelength ones probably similar to your keychain light.
the difference is the Arc UV is not as bright but flouresces things with much more intensity.
it's that combination that makes the Arc UV great to use.
in the dark, it will make flourescing objects shout out to you because of the fact there is little visible light coming out of it while still maintaining a great flourescing ability.

@LEDite and xenopus, both you seem to have lots of experience with UV LEDs and UV lights, i was wondering if you will be utilizing the new Nichia high power UV LED which came out this month, this is different than the 5mm used in the ArcUV. here is the Nichia UV link. they have a 365nm and a 385nm model.

 

[DM51]

MorpheusT1 modded a KL1 with a UV emitter, and I now own this. It is extremely bright and throws very well indeed. I don't know if he is doing any more, but it would certainly be worth asking him.

 

[LEDite]

The Day;

I have not tried the Nichia UV LEDs.

They are only rated @ 500 ma vs. 700 ma for the new Crees.

In my applications, 40% higher power has always been better.

Isn't that the Flashaholic creed ??

Larry

 

[winston]

The Day;

I have not tried the Nichia UV LEDs.

They are only rated @ 500 ma vs. 700 ma for the new Crees.

In my applications, 40% higher power has always been better.

Isn't that the Flashaholic creed ??

Larry

Sometimes it feels like the 40% higher power is in the form of so much purple light that it overwhelms any fluorescence that might be there. Anyone else?
-Winston

 

[THE_dAY]

hi LEDite,

the Cree is rated to be 395nm- 410nm correct?
i guess if one is looking for a lot of purple light output then the Cree would be a good choice.
i haven't seen one in person, how is it at flourescing objects?
someone had mentioned that their 1 watt Cree UV light does not pick up the flourescence in currency.

the reason i brought up the new high power Nichias is because if it's anything like the new 5mm Nichia in the Arc UV, then it would probably be amazing at flourescing objects.

what i'm trying to say is the new high power Nichia UV might not put out a lot of light compared to the Cree, but their "glowing up things" factor is what i'd be interested in.