A little late to this thread, but just in case anyone is still around….
I noticed a significant amount of reflection from the ZWB2 filter. Did some investigating into AR coatings and got back ridiculous prices. So I emailed Simon and he said the factory could do it at a very reasonable cost.
Any thoughts? My research shows that a 10% to 20% improvement in output might be expected….
I’m around
That is a lot of improvement, so reflection on the glass surfaces from UV is worse than with white light, and so there is more to fix for the AR coating!
Nice of Simon that he is willing to do that, I’m certainly in for some of those if the price is reasonable, AR-coated ZWB2 filters should look cool too btw.
He quoted $3.83/ea which is the same price he sells two of the non-coated filters for now. He says they need to be produced (manufactured) and will get back to me. Will keep you informed
I’m interested in a couple at least. I have two Nichia NVSU233A-U365 1030mW chips on the way right now. My first uv emitters so I’m trying not to get too excited.
Yes,on aliexpress there is a mix of offers with random thickness and diameter, sometimes more offers, sometimes hardly any. Usually tens of dollars for anything more than 25mm.
Pardon a dumb question. I ordered a set (2pcs) of ZWB2 filters from Simon’s Convoy store in AliExpress and it just arrived a few days ago. I’m wondering when I place the ZWB2 filter inside the Convoy S2+ UV Nichia flashlight, can I place it behind the existing plain glass lens (which is what I just did — so it has a plain glass lens in front, and the ZWB2 filter just behind it), or do I need to remove the plain glass lens altogether (ie. only the ZWB2 filter)?
When shining some other light on the ZWB2 filter, it looks like it has concentric circles/rings, though I don’t notice the concentric rings when using the Convoy UV w/ ZWB2 flashlight…
Yeah, when 2 pieces of glass get close enough that there’s a very small air-gap, you get funky optical properties. Some places would be in contact, some places would have a clear air-gap, others would be in that twilight zone in-between where it’d essentially be a vacuum (ie, other than maybe H2, no molecules would be able to fit.
So what you’re seeing is a sort of standing-wave of the 2 distinctly different interfaces: glass–glass, glass–air, and glass–vacuum, and the different refractive funkiness of each zone.
That’s why I don’t even like to keep the original glass when refitting with a TIR. Weird things can happen.
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Oh, wait a sec… you mean just the nekkid ZWB2 filter and no other glass on/under it? Hmm, never really noticed that. Will have to look.
^ ah, now I see what rings were meant (they are called Newton rings, an interference effect between layers close to each other, close to parallel but not exact.)
Learned something new today. Yes, Newton rings are indeed what I’m seeing.
Thus by placing 2 pieces of glass (the non-AR-coated glass lens and the ZWB2 filter) close together, there is indeed an air-gap between them that causes these Newton rings… I wonder which one is the slightly convex curved glass — the plain glass lens or the ZWB2 filter — more likely the ZWB2 filter?