Review: UV light shootout, seven lights tested

Wow, Teej. None of my UV lights even remotely compare to that. Looks great. Thanks for posting those pictures. That totally answered what I needed to know. Thank you again.

Your work sounds interesting and challenging. With the broad spectrum of projects you work on, it sounds like you need to do research at the same time you're investigating sometimes. I'm sure it has some tedious aspects at times, but it definitely not cookie cutter type work.

The variety is what attracts me to it. Now that I’m “retired” I can do what I want to as long as there’s cash flow. :smiley:

I don’t find research to be tedious, I like investigating things…and there’s always SOMETHING to be learned in the process, even if its not relevant to the original question.

That’s one direction that took me in search of newer UV lights in the first place…I saw something that my current light could not do, and wondered why…back in the 1980’s, and delved into the wavelengths, etc…and what reflected UV vs fluorescing UV was able to resolve, etc. After that, when LEDs came out, I started to be interested in that format. The electronics for example is not a long suite though, and that’s an area that I can delve into deeper, etc.

I have so much to learn, as relatively speaking, I am only familiar with HOW to use various lights, but relatively speaking know almost nothing about how they WORK electronically.

:smiley:

Brilliant! Sounds like a lot of fun and rewarding too.

I’ve built hundreds of UV lights in the last few years.

This is the most popular 6 watt input model:

This one is my newest AC powered with 24 input watts:

I use both 365nm and 385nm LED’s.

Overall, the 385nm LED’s provide better fluorescence,

mainly because they deliver more mw.

Power is Panasonic 3400mah cells or AC power supply.

LarryDFW

What model emitters do you use?
LED Engin seems more availble then nicha emitters.
I recall reading on LPF about some really pricey emitters you had a few years ago.

Helios;

I am using a variety of emitters in my UV lights.

I have tested Nichia, LED Engine and EpiLeds UV emitters in a variety of configurations.

It is a constantly changing scenario of who is delivering the most mw of UV per watt

at the desired frequency.

By the way in my testing, I’ve discovered that nm advertizing is unreliable.

And in talking to Luxeon a week ago, they said that NO Luxeon UV leds have been released.

They are working on some.

LarryDFW

Hey Larry :slight_smile: I sent you a PM.

-Jamie M.

I suppose it depends upon what you are fluorescing though, as some materials simply need shorter than 385 nm UV to fluoresce. IE: They don’t at 385 and do at 365 for example.

The problem is that the emitters are much BETTER at converting the cell’s power into mW if its mW of 365 than 385 nm UV light.

I use UV tracer dyes for certain applications, and dyes that work at 365 nm by design may not work at 385, whereas most of the 385 dyes also work if 365 used used to excite them.

There are rare instances where something can work at 385 and not at 365, but, typically, its the other way around in actual use.

Some minerals will not fluoresce at 385, OR 365 nm for example, its still too long a wavelength…and they require even shorter wavelengths.

The only time 385 will work better than 365 is if 1) 385 is short enough, and 2) It just needs a higher mW exposure to make it fluoresce…and the 385 can use the same power to get a higher intensity exposure, using the easier to emit longer wavelength….than the 365 can.

In practice, the higher energy of the excitation from the 365 will compensate for that, and things will generally fluoresce better. If the targets are MADE for 385 nm, say currency, sure, 385 will work better as for the same powered light, more 385 mW can be applied, etc….IF power was the limiting factor.

:smiley:

And, I may want to interest you in some future projects, as while I might use my UV differently than you do, so our experiences are different, YOU understand the electrical aspects, and, I am seriously lacking in that department. I am more involved in the chemical/biological, than the electrical, end of things.

:smiley:

Not from what I’ve seen… you can get much more 385 nm light out of an LED than 365 nm… the shorter the wavelength, the larger the electron band-gap jump needed to produce it… and as a rule, the less efficient it will be.

I presumed that was just a typo & he meant it vice versa.

LOL

ooops

Yeah, typing on phone/lack of proofing.

:smiley:

The emitters, we agree, are better at longer wavelengths, IE: For the same juice, they can make more 385 than 365 nm.

The point was that some things DON’T fluoresce at 385, and will at 365 nm….so while the LIGHTS can more easily make things that do work at 385 nm light up, the potentially higher mW of 385 nm lights will not make a material that needs 365 nm fluoresce.

If bills for example are MADE to fluoresce at 385-390 nm, then you don’t NEED 365 nm to light them up, and, a stronger 385 nm, which is easier to attain, WILL work great.

For other materials, you can shine all the mW of 385 nm you want at them, and they won’t fluoresce, as they only get excited by shorter wavelengths…some shorter than the 365 nm as well, and so forth.

This was primarily in reply to the statement that 385 nm provides better fluorescence…and the context added was that that applies only if the material is fluoresced by that long a nm range, and that 385 nm will not provide better fluorescence for materials unless its mW limited instead of wavelength limited.

I did a succesful flashlight mod with a newest Ledengin 360-370nm led, thread here :-)

Is anyone using a Wood’s Glass lens?

I just got two Solarforce UV P60s — one works fine; the other one, shortly after I put it in the Solarforce host, I dropped it (about 2 feet) and the LED came unstuck from the pill. So I’ve got to figure that out.

But — one works fine.

I went looking for a way to filter out the visible and not interfere too much with the UV output. Rosco makes theatrical filter gels that might do, but the UV would eat them up pretty fast and they lose a lot of transmission even in the UV range. But.

Aha!

I found mention here: http://www.rosco.com/spectrum/index.php/tag/blacklight/

“… Rosco’s new Permacolor #3660 UV Pass Filter in front of a UV-rich source will do the trick perfectly.”

Those cost around $8 from photo suppliers for a 2” circular filter.

Anyone know a flashlight that takes a P60 dropin and will hold a 2” filter?
Or a flashlight that will take camera step-up lensholders from its standard head to mount a 2” filter?


Edit: and here’s another, one guy on a blog said it’s a better filter:
http://www.newport.com/Bandpass-Filters/417890/1033/info.aspx?gclid=CNiezNqc4bYCFUeCQgodilAA-Q

If it’s from Newport, forget about it… unless you are a very stupid Bill Gates… as in Billionaire Gates. Figure $400 each…

I got the drop-in the other day and put it in an L2P with 2 extension tubes, running 4 18500 lap pulls in it. Very low visible light, but very strong UV. Can’t see it in a beam profile more than a few feet away, but in a dark room it will flouresce virtually anything in the room. Haven’t tried currency yet, but diamonds really show their stuff! And the emitters, yeah the MT-G2 is awesome looking at a bright reddish orange! Gotta be careful not to flash the UV back at yourself though. :wink:

How important is it to run that high a voltage? Would be much more convenient to have a smaller light, but if it needs that kind of power to really work then I’ll leave it set up as it is.

Thanks again!

forget Newport, different technology, no doubt $uperior (sigh) but not for $400

The Rosco UV-pass filter costs $8 to $16 from a lot of photography stores.

So — does anyone make a flashlight that takes a P60 dropin, and has a 2” (50.8mm) lens/reflector diameter??
Or know of step-up rings that would put a 2” photography filter on a flashlight?

Threads. Drive. Me. Crazy.
Seems like machinists have more different kinds of threads than quiltmakers!

Hmm, anyone tried the new Nitecore UV light?
<a href=“http://illuminationsupply.com/chameleon-series-c-c-28_53_127/nitecore-chameleon-cu6-xpg2-440-lumens-ultraviolet-365nm-1-x-18650-2-x-cr123a-p-950.html”/a>Illumination Supply has the Chameleon CU6 on special right now and it claims to have a 365nm LED.

Just curious. I doubt it would compare to a multi-hundred-dollar dedicated UV light, but it’s nice that it’s useful for general-purpose lighting instead of just UV. Low-power red/green/blue emitters, a “3 watt” UV emitter, and the XP-G2 we’re all familiar with, in one package. I’m hoping someone will review it soon. :slight_smile:

I wish manufacturers would say which UV LED is used (brand, model, etc.) as we are always told of “Cree” as a selling point. >.<

I have found that even with current U.S. currency bills . . .

the dyes used are excited better at different nm wavelengths.

LarryDFW

“… remote control monitoring stations up/downwind or stream from suspected polluters and collecting evidence over many months to find patterns of releases to the environment that a single inspection would probably miss (Already missed typically…).”

Thank you.