The power can only be helped with more LEDs, but for a wider hot spot you can try matte scotch tape. You know, the “invisible” kind that isn’t shiny:
Apply it directly to the flashlight lens. This will diffuse the beam, the more of the lens is covered the more diffuse it gets. If you don’t like it, just pull it off again.
They are easy to find. Just slather your body with steak sauce and go for a swim… all sorts of shark teeth will come to you. J)
[quote=HestbechI don’t think any of them ever exploded in my time (I’m 34 years old). Most of them are really rusty. I think it would take a Tank to set them of - if they even still contain intact explosives :-p[/quote]
Easy way to find out… just whack them with a hammer. J)
Just because they are old, doesn’t mean that they are dead. Like people, old ordnance tends to get rather grumpy and lose their sense of humor as they age.
texaspyro - lots of good ideas. Will try the steak sauce method. Not any big sharks in the Danish waters though. Could hope for a gentle bite from a seal maybe.
Lol -didn’t realize i wrote 34 years until i saw your quote. Must have been a “wishful thinking - slip”. I’m 39 
Confusius - that’s an awesome MacGyver mod. Will try that!
I'm glad the light works for the purpose :-)
My guess is that you will loose too much spot intensity like that, but you could try, easy enough to pull it off again. It just is not easy to get a large spot and high intensity at the same time, your led output power will have to explode to get that done. A bit more power should be derived from the Luxeon Z UV, super small die and high output. It is available from 380nm up (no 365nm version). Perhaps customlites can make a drop-in with that one, or a high power Nichia of 400nm (that will not be budget, as you already found out).
Could a high powered Led like one of those be installed in a Convoy C8? Or would it run hot?
I think i totally dropped the “tripple Led in one flashlight” setup. It would be stupid to go “all in” on something that might be outdated in a month or so. Or if I discovered that 400nm was best, after buying 365nm.
I think the most versatile/customisable (and ugliest) setup would be 2 or 3 C8’s in some kind of mount attached to a handle.
Maybe combining the handle LinusHoffman used for his BTU shocker, with some different rails and clamps , so the flashlights are side by side, or in a triangle (depends on the number of lights) under the handle.
Hi all,
A friend of mine emailed me some UV LED comparison images regarding amber searching from this thread. I thought I might have an interesting comparison for you so I registered here, and this is my first post…
I have an EagleTac T25C2 which I factory ordered with the 365nm LEDengin LZ1-00UV00 drop-in. It seemed to put out quite a hefty amount of UV, but also a fair bit of visible light, as many on this thread have noted. I initially thought this must be a common thing with UV LEDs but at least with this one, it was putting out some dim white light and not a horribly bright garish bluish/purplish visible light that I’ve seen from some other cheap UV LEDs.
A few months later, I also ordered a Nitecore CU6 when I saw a good sale price on it and while not expecting it to be as good as the EagleTac for UV work, I thought it would be a very versatile light, easily switching between UV and white LEDs with some 5mm colour LEDs thrown in for good measure. The Nitecore CU6 seems to have a 365nm HPL-H44LV1C0 UV LED, at least that is the closest match I’ve seen made. In any case, much to my surprise, the CU6 had way less visible light output than the EagleTac and offered a huge improvement in contrast, and this for a light that was only about 1/2 the price of the EagleTac!
I started to regret my EagleTac purchase but after some experimentation, I decided to order a custom cut Rosco #3660 Permacolor glass dichroic “Cold Mirror” filter. It was surprisingly inexpensive to have this cut to the exact diameter of the factory lens in the EagleTac and although it was a hair thinner, it mounted in place perfectly and it even feels as though the o-rings are tight and that the light would likely retain its waterproofing. This is definitely not an ideal filter to use, since it does have some cutoff at 365nm, but it was the only one I could easily order precisely cut to size. Sadly, the Rosco #3650 would have been ideal but is not longer being manufactured. However, even the #3660 has made a truly massive improvement to the light’s usefulness!
Here is an animated GIF showing a comparison, 4 second pauses between frames. A glass diffuser which does not absorb UV was used, and the lights were exactly 5 feet from the subject. The exposure used is shown on the control (dark) frame at the start and all shots use this, except the un-filtered EagleTac. It pumps out so much white light that the shot would have been very much overexposed, so instead of a 30 second exposure, that frame only had a 10 second exposure. However, our eyes adjust very well to variations at these low light levels and the animation as I’ve shown, does represent very closely what I see visually, although with dark adapted eyes, the pure UV is still brighter than it appears here…
So, as you can see the contrast increase with the filter in place is massive and even though it likely does cut down on the absolute UV output a bit, it is still brighter than the bare, unfiltered Nitecore CU6 UV. In addition, you can see that some fainter, dark orange elements of the rocks in the photo stand out far better with the filtered EagleTac than with the CU6, in addition to the fabric in the camera bag on the right. While I don’t have any amber readily at hand to test, I do believe the filtered LEDengin combo would probably be an effective amber searching tool. There are better filters available from Hoya and others, but none can be as easily purchased to spec, already cut to the right size to actually replace the front lens of a flashlight as easily as from Rosco, at least as far as I know.
For a larger, 1600 pixel wide version of the above animation, click here. If anyone wants to see a post with larger, non-dithered individual JPEGs of the test shots, let me know and I will do so?
Lastly, I have to say that I really like the versatility of the Nitecore CU6. While its UV LED is not optimal, it also has very little residual white light and being able to rapidly switch between a dim, 1 lumen white LED and the UV LED, just by pressing either of the two mode buttons on its side, makes it very easy to spot UV active items when exploring. The easy white/UV switching also allows one to more easily navigate in the dark with only a single flashlight in the hand… something I now appreciate after stumbling on a rock in the Arizona desert, in the dark with only the EagleTac UV (Armytek headlamp switched off for better UV contrast), brushing a cactus and getting a butt full of Cholla cactus needles - ouch! 
Anyway, I hope that some of you have found this comparison useful… 
If anyone is really interested, I do have access to some polished and cut amber jewellery that belonged to my mother and I would likely be able to borrow it from my dad to do a few test photos. Actually it would probably just be easier to photograph those at his place at some point…
Thanks for the contribution mmander, and welcome to BLF :-)
That looks like a very useful filter, and a pity that the exact right dichroic filter was not available in the right size. I now wonder what the difference would be between between the Ledengin+filter and the Nichia led that I tried on amber above. Nichia uv-leds have always been very expensive and this is the first one that is a bit affordable, at about the same price of the Ledengin LZ1, but it has a bit lower output (small test of the Nichia here: https://budgetlightforum.com/t/-/31647 )
BTW, I followed the link in your sig-line: you make some amazing pictures!
Welcome to BLF mmander! Your photos are quite amazing!
Welcome mmander! Quite new on BLF myself. Also signed up on candlepowerforums - but I’ve gotten a lot more response here on BLF.
Awesome pictures! Nice to see the Rosco #3660 in action.
Made a google search on HPL-H44LV1C0 uv Led, and ended up on the tread you participated in over at CPF. Again - AWESOME pictures! Those closeups you took are so crisp and clear 
:heart_eyes:
As you can read from this thread I’m really digging into the “scientifics” of uv induced luminescence of amber. Well more of a hands on approach rather than scientific - primarily djozz is providing the know-how and science
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If you find the time that would be fantastic. Especially the effect the Rosco #3660 glass have on visibility of the luminescence would be interesting.
Where did you buy the custom-cut glass? Can’t find any resellers here in DK. Oh - and does the Rosco glass heat up from absorbing the visible light?
Thanks for the kind welcomes! Glad you enjoyed the photos.
Glad you liked the closeups in the other thread.
I manage the digital imaging dept. in a pro camera shop in Vancouver, B.C. and I actually ordered the custom glass filter from the Rosco distributor in Canada, through our guy that does the filter orders at the store. He definitely looked at me funny when I said I was ordering it for the front of a flashlight! :bigsmile: If you are interested, I could probably arrange some special-order filters, cut to size and I imagine they’d be cheap to ship via postal service? I am not 100% sure, but I think the retail price on the one I had custom made for the EagleTac was around $20 or so. However, I’d suggest just going to any local pro camera shop where you live and asking them if they could arrange a special-order from Rosco for you.
What worries me though, is that I can no longer find the #3660 on any actual Rosco website, only mentioned on other sites that resell Rosco products. Our distributor claims it is still available, but I am not convinced they are actually right about that. I am getting our filter guy to pressure them into really checking into it and not just assume.
An update on the situation with the #3650 filter too, one I didn’t mention in passing before, is that Rosco could indeed do another production run, but I would have needed to order a minimum of $900 worth of filters/filter-material! 
I am now slightly worried that maybe the same situation exists with the #3660. I made the mistake of lending the second backup filter I had ordered at the same time to customer who was actually using it to do genuine narrow-band UV photography with it (using it in front of a lens) but he has had it for months now and I’m concerned I may never get it back. I had not been worried about the money, since the cost was minimal and before, I had thought I could just re-order another one for myself if need be. Now I’m not so sure. Also, the filter seems to have a delicate and fairly easily scratched silver coating on it (it looks just like a mirror), so even if I get the second filter back, it might have been damaged with all the use. Crossing my fingers now that I see the customer again and the filter is returned relatively unscathed…
Having custom filters cut by Rosco is pretty neat. I have replaced the front glass in both my Nitecore SRT7 and my EA41 with slight warming filters, ones that tone down the overly bluish cool-white tint of the XM-L2 LEDs used in those. Being a photographer, I am also a bit of a tint-snob and severe off-neutral casts in lights drive me nuts! Adding those filters has made a huge difference for me and now I actually like using them! 8) My favourite flashlights for visual tint though are my MT-G2 lights (EagleTac MX25L3, SupBeam K40Mvn) and for photography, my Nichia 219 equipped EagleTac MX25L3C.
Anyway, I will try to take some comparison shots of the amber jewellery, along with some UV inert rocks as well, sometime in the next week or two. I might be out at my father’s house next weekend and I’ll bring my camera gear and UV lights. At present he is away traveling, so hopefully I can find where the amber is stashed. I know that before my mother passed away, she had her jewellery scattered all over the house, much of it wrapped in cloth and stashed in small innocuous boxes behind books in book-shelves and so on, just to make it less of a target in a potential break-in. No locking safe in the house and her locking jewellery box that she would hide when away, was far too small for all of it…
Almost forgot: no I don’t think the Rosco glass heats up appreciably since the visible light is only on the order of a few lumens. When on full output, the head of the EagleTac UV does get warm, presumably just from heat dissipation of the LED, but never really hot.
At work, in our rental dept., we actually have a large, genuine Woods Glass filter that can be used in front of a studio strobe head to filter all visible light and generate bright pulses of UV for photography. I imagine that filter would heat up a lot, since a single full-power visible light pop from one of the big strobes can actually melt plastic at close range. I tested that filter with the EagleTac and saw how big a difference it made, which is what led me to order the Rosco…
I did all my shark tooth hunting in piles of rocks that were ready to be spread out for driveways in eastern NC. I guess it was ocean dredge or something like that, forgot what they called it.
Thanks for the offer
I wrote a mail to a Danish reseller to see if they have some samples to do some testing on. They would look into it - but still waiting for a reply. But i might get back to you on you offer 
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Hmmm - maybe we should arrange for a group buy. If they cost $20 a piece that would only require 50 orders to reach a minimum of $900.
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tint-snob. LOL!
I'm starting to give up on finding a good triple host to build up into a UV-flooder monster-light. At this point, I'm starting to consider sacrificing my old 5-emitter TR-1200 for the build. Replace the XR-E emitters with the XP-sized UV emitters... Should run well with the factory driver and no other mods.
Curious about the beach amber hunting... Is that something that is European only or is it world-wide? Should I expect to find any at the Gulf of Mexico/Texas coastline?
Anywhere for amber hunting on New Jersey shore line? I tried to google for a good spot and found none.
Really interested. That is a great reason to get a quality UV light.
I’m thinking about making a setup with three separate C8 sized UV flashlights with different wavelengths - and constructing some kind of picatinny rig with all three flashlights under a handle. Low-tech, but easily customizable.
Actually don’t know where finding amber is possible. I read something about it being mined somewhere, but cant find the link. Will post it when i find it.
Seems to be mainly a European thing
Edit:
This is the link i was referring to
http://raw-amber.com/natural-amber/about-raw-amber.
And as the high tide is 20 minutes ago (time is 21.23 here) I’ll pack my bags and go to the beach
I'll likely be headed down to the Gulf in May, I think I'll take my UV light with me then and see if I can find anything. I'm not feeling very optimistic though...
