Review: UV light shootout, seven lights tested

Then a needle test. Glass sould not let the needle stuck by pushing it on the lens. Try on the edge (to avoid having some visible damage) if you're not concerned knowing you have a 0,3mm hole in the plastic lens somewhere.

First it looked like plastic because of some very small scratches, but maybe it is coated glass, I noticed that reflected light shimmers somewhat on the surface. It is specified as "Toughened ultra clear glass lens with AR coating" on the Tank007 site, but I don't trust these specifications very much. I wouldn't try with a needle...

I didn't try to open the head, but it took a lot of force to get the tailcap off the light when inserting the battery, so I would assume that the head is just tightened very hard. I don't see any glue from the inside either.

Then it's probably glass with plastic AR coating.

Thanks, mfm. That had to take a while to put all of that together, let alone the time it took for you to run around to all of those different countries. I didn't even realize the extent to which UV is being used in notes, but it was fun seeing all the different possibilities.

Comparison added to the first post.

I wonder if the T5 light is a bit underpowered, I run it with 4 x Eneloop AA but the voltage for the T5 tube should be 6V (the manual says to not use rechargables but that's usually crap). May have to find some alkalines just to try, don't have four of them at home.

Looks like the TK is better regardless of the voltage to the T5.

It's not only that the T5 is weaker, it also seems to not cause fluorescence at all in some of the places the TK does.

But maybe it really is just the input power.

I tried with four alkalines today and no noticable improvement, as expected.

But it seems to me that that the T5 causes fluorescence in all the same places as the TK? Just weaker and it's not that easy to see on the pictures (and the green part of the euro is very hard to see because of the violet light).

Even though this 4W version is a little hard to use because of the visible light, generally there is no doubt that fluorescent tubes are way superior to LEDs for generating 365nm (or lower) UV. Even if you buy a Nichia drop-in for 160 EUR it will be easily outdone by a fluorescent lamp costing much less (but the LED is easier to bring with you).

I really need to buy a fluorescent one some day.

Where did you buy yours? I remember a seller on eBay that had them but I can't find him.

There's also a comparatively cheap 254nm version: http://cgi.ebay.com/254nm-Ultraviolet-Pocket-Lamp-Shortwave-Bonus-M12_W0QQitemZ370510530344QQihZ024QQcategoryZ3226QQssPageNameZWDVWQQrdZ1QQcmdZViewItem#ht_3228wt_1139

I wonder how safe it is... and how effective it is.

I bought this one, it's even cheaper now than when I bought it: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280590817370&ssPageName=STRK:MEWNX:IT

But you don't need it if you have the TK...

Shortwave UV is much more dangerous so I wouldn't bother with it. With high-powered shortwave UV you must have both eye and hand protection, maybe the 4W isn't that powerful but anyway. I already had enough trouble from the lights I own, briefly I looked into the 3W drop-in without thinking when I had the protection glasses on (not a great idea).

Here is how bright a banknote fluorescences under a high-powered tube light, I would guess it's a 16W or 20W tube: http://www.youtube.com/watch?v=JNKkCmXBAg8&feature=related

Looks like the TK is the only one worth bothering with. The UK mint warns that no LEDs are likely to give short enough wavelength light to check the security features

http://www.bankofengland.co.uk/banknotes/kyb_lo_res.pdf

It seems that some of the pictures with the TK-566 were taken when the battery was low (AA powered has it's drawbacks), I have uploaded new pictures of the 500 CZK and 1000 JPY notes.

Thanks mfm! Wow, this is an incredible amount of effort. You really outdid yourself on this one. Nice collection, and incredible shots!

Frontpage'd and Sticky'd for sure.

Thanks!

I added some more shots: the 5 USD vs the 20 USD and some more Czech and Swedish banknotes.

Thanks for all of your hard work mfm!

They really are great photos, it's a little glimpse of something we normally don't get to see. Which is rather a shame as they really are very nice.

Random question...I know some insects can see UV, bees for instance. What would they see if they looked at these notes in day light?

It's not something I've thought about before so it's intrigued me, would they see nothing as we do or would they see non-glowing marks.

I assume the ink that the marks are made with is transparent to visible light, but perhaps not to UV..but really I've no clue :P

I added the backsides of all current Chinese banknotes, I think they are quite nice.

I really like the performance of the TK-566 and am interested in buying one for my mom who is a bit of a geek when it comes to such things. She's familiar with the dangers of such things and would know better than to look directly into the light. Outdoors in the dark, what is the range of this light? Is it best for up-close only such as checking bank notes? Tomato worms are known to fluoresce under a blacklight and she wants something that could be used to sweep tomato plants after dark looking for them. Which UV lamp would be the best projector?

I have the Tank007 PT30 3W 365nm version, which has 3 of the LEDs of the TK-566 and also a slightly larger reflector. I also have an O-Like 405nm 400mW laser. Even taking off the focusing/collimating lenses on the O-Like (ie RAW diode output), the "UV" of this O-Like causes things to flurorescent more and has a longer throw. The PT30 has a longer throw as compared to the T5, but when you are checking out urine stains on the latrine bowl, the PT30 does not really show this while the T5 shows it clearly (just that you have to bring it really close).

The PT30 has a wee bit of visible dull white output in addition to the UV. If your prescription glasses has UV filtering, no issue. Mine is transition, and it even filters the really powerful non-focused raw output of the O-Like 405nm completely.

But for regular stuff like orange/yellow fluorescent stuff, some types of paper, toilet paper, the O-Like 405nm really causes everything to glow crazily. Focus it correctly, it makes stuff 300m away glow as well, eg a white T-shirt. (that distance is farther than the NOHD, so no danger).

BTW it is not Nichia as mentioned in the video (it was advertised as Nichia on aliexpress). Someone said Edison, whatever. A 3W Nichia NCSU033B one was selling for usd300+ on aliexpress.

http://www.youtube.com/watch?v=yoTYspNclLA

http://www.candlepowerforums.com/vb/showthread.php?311637-Need-help-in-identifying-UV-LED-(advertised-as-Nichia-seems-not-one)

I tried to take a video of the O-Like 400nm RAW diode output with the same settings as the 3W 365nm LED, not good it just overexposes everything.

That 50Yuan note is especially nice, nice UV sunrise :)