2mm ZWB2 filter tested (visible light blocking filter suitable for 365nm UV flashlights)

Is the coated version still available somewhere?

I do not understand, the coated version of what do you mean? (ZWB2 filters as far as I know are not coated).

There was a coated version mentioned above but I don’t know if it was released.

Ah sorry, I see, I should have read some posts back, the discussion is from last year and apparently I’m so senile already that I totally forgot.

I guess Simon never went on with it and pirate stopped bugging him about it. It is not in his store at least.

Ah that’s sad. The coated version would have been an even better addition than the non coated filter I think.

Just reread this post - forgot to update -sorry. Upon further investigation I was told that AR coatings are not really efficient for UVA and result in a significant transmission loss, so I just dropped it (sadly don’t remember the details). Of course I’m sure there are specialty houses which can create very efficient coatings, but at a very inefficient price (I was quote a couple hundred for one piece, and a setup charge as I remember).

Thanks for the research! Sometimes we gain nothing by investigating things, sometimes we find very useful stuff.

Thank you for the update.

Been looking on aliexpress and there is a bunch of sellers of the stuff there.
Is this glass required for an LG3535LED? I bought it assuming it was much better than a chinese brand in regards to the visible light output.
Specs on the LED are 380-385nm, but i see other sellers selling it under different wavelenghts and I question whether or not hose ones are genuine.
I cant find any datasheet from LG either.

The filter is for eliminating visible light. The Nichias emit the least with others emitting somewhat more. The cheap ones are the worst. You will enjoy the light more if you get the inexpensive filter. ,

i found them to work but they are very susceptible to breaking and chipping

i think the glass is soft, somehow

wle

Judging by the various price ranges for ZWB2 filters, i assume they’re not all the same quality.

true, and quality may not be entirely defined by glass hardness, either
mine were certainly cheap

wle

Yes im aware of that, I was trying to work out if the LG3535 puts out excessive visible light compared to the cheap chinese LEDs on the market.
Im wanting to use it on uranium glass most of the time and the odd time to cure UV resin.

i’m a uranium glass guy

i have found one hack for that, for testing it in the field, a cheap purple laser has tons of UV
you can even use it in day light
which no flashlight alone can overcome

lights it right up

wle

Yes ive been over in laserpointerforums and quite a few are doing that with purple lasers.
Im currently building a blue laser with an M140 diode.
Will need to build a purple/violet laser to get the UV, i dont think 445nm lasers produce any.

+1

My current ZWB2 filter supplier is KD, good quality and has several sizes.

Be very careful around other people with those, both direct and specular reflections.

The human eye is just barely sensitive to those wavelengths, which means it takes a heck of a lot of photons before your visual system tells your brain it’s seeing anything. But just because you can barely perceive the light output doesn’t mean it’s not transferring a lot of energy to the retina.

This should help: Ultra Violet SUPERPOWER (!) after Cataract Surgery with Crystalens - color glow
He had cataract surgery and was given intraocular lenses that don’t block UV, so he can see what most people cannot.

Yes, Im aware of the dangers with lasers. As long as you are not pointing on shiny objects in the near field of view, its quite safe.
My laser can also focus like a flashlight with a wide throw, which reduces the danger completley. This makes them perfect for shining on uranium glass.

Right now, im more concerned about the dangers of UV lights.
Seems you are supposed to wear glasses for these too, which I dont fully get, since its all UV-A, which is supposed to be the “safer” part of the spectrum.
This cheap light I got from the electronics store says it can be used as a fun kids toy! Yes im serious, says to use for spot light games, etc.
Ive also been to many public events where you can see the UV blacklight tubes glowing that magical violet directly. One place I saw they were using the 365nm tubes once as they were not the typical black colour. I didnt know anything about this at the time, since I was just a kid and thought it was fun lol.
Not that ive intentionally looked into it, but have accidentally shone in my face when handling it a couple of times.

From what Ive researched, we are exposed to way more of this same part of the UV spectrum each day from the sun, so im not too sure how dangerous this cheap 3W light of mine is. I expect it would be around 395nm.

Its interesting read in that link of yours.
I did not know our eyes started to block out more UV with age. I guess this is a built in means of protection, a bit like how your skin makes melanin with UV exposure?

The lenses in our eyes develop an amber filter over the years.
This is a degradation rather than a feature.
But it does make the world look a bit warmer, i suppose…