depends a bit on what wavelength. The 395nm light from the light in the OP needs yellow /amber glasses, the 365nm leds can be be blocked quite well with common polycarbonate glasses (most ‘impact’ glasses used in workshops and labs are made of polycarbonate).
A quick test is always: shine the UV-source onto a sheet of copier paper, all UV sources should make it fluorescence bright blue. Then place the glasses in between light source and paper and see how much fluorescence is leftover, good glasses make it almost gone.
I use uv strips on my boat for night fishing and some of the strips from China last about a month don’t know about individual leds anf how they will hold up in long run.
I used a cheap $5 pair of yellow-lensed safety glasses from Wal Mart with my 395 UV light and they worked very well. They effectively blocked the majority of the visible blue making fluorescence pop much more vividly. Even dark items were more dramatic, such as leaves that fluoresced red, and tiny mushrooms and other fungus that was washed out in the blue. They also passed the paper test Djozz mentioned; shining through the lenses would eliminate fluorescence, and my eyes could feel the difference too.
It’s close enough, just like djozz said. I bought a whole bunch of different wave lenght uv leds from there from 365 to 410 so I know the difference they make. Only the 365nm led was able to match the performance of my mini uv cfl lamp when checking currency.
The case with aliexpress is that everything depends on the seller. Some are genuine while most others are not. Remember Convoy and Soshine have their official stuff sold through Ali.
it sure does work, i’ve build few uv lights using pmma tir lenses. have leds run for hours, no issues whatsoever.
i thinki know what picture you talking about, however it shows carclo triple, which is made of polycarb.
has nothing to do with luck, polycarbonate lenses are ok from 400nm, and up, never had any uv led damage lenses, but than i never drive them beyond reccomended current, in most cases i drive them with even less current, uv leds are not nearly as tolerant to heat as white leds, so no overdriving, 365nm will be fine with pmma, done it more than once.
I just tried the polycarbonate (clear safety glasses) and paper trick. It did reduce the fluro pop some. I then tried with/without the optics and there didn’t seem to be much difference. Does that mean I could’ve used 365nm without issues?
paper will glow at basically any wavelength, even blue light makes it glow a bit. find something else to test, id, or money, or something else that reacts to 365nm, but not to higher band.
also, are you sure your tir is not a pmma one? such 7up lenses are made by different brands, and some no name brands. also pmma is basically an acrylic plastic just not as brittle, acrylic does let lower than 400nm thru. simple common Plexiglas is acrylic.
You cant test a lens with 400nm and then use 365nm and think it will work
PMMA woks down to 385nm, Polycarbonate 405nm
It is quite simple if you test a lens or TIR with 400nm with paper of course the paper will glow as the material transmits 400nm very well
But if you go 365nm or less what looks to your eyes and 400nm as transparent becomes black as it absorbs the light
Absorbed 500-1000mW in a few cubic mm of plastic resulted in a molten and burned optic, unfortunately this picture is gone with photobucket
the pic is still there, it is polycarbonate carclo. he said he used 395nm leds to burn the tir, no indication how hard he was driving it . my guess he was driving it above recommended current. but i might be wrong https://s17.postimg.org/tbyqf3qrj/DSCF6042_2.jpg
