Blocking violet light leakage in UV lights

  • #1
Garlic
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Hello,
I have a handheld UV mercury vapor lamp, which, when working, leaks some visible light around violet wavelengths.
My question is whether it is possible to block violet light but let the UV light using some kind of colored transparent sheets.
Thank you..
 

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  • #2
sophiecentaur
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I would imagine that the present filter that's on the lamp was chosen on the grounds of cost. It will be doing the job according to the spec of the lamp. I have a feeling that you would need a different kind of filter (interference filter) that would have a sharper cut off between visible and UV. That could cost you more money.
I googled UV bandpass filters and found a number of hits. It all looked pretty expensive stuff. :frown:
 
  • #3
Garlic
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I would imagine that the present filter that's on the lamp was chosen on the grounds of cost. It will be doing the job according to the spec of the lamp. I have a feeling that you would need a different kind of filter (interference filter) that would have a sharper cut off between visible and UV. That could cost you more money.
I googled UV bandpass filters and found a number of hits. It all looked pretty expensive stuff. :frown:

Oh.. :frown:
Why isn't it easy to find a such material? Ultraviolet is just another color that we can't see. I can block a wavelength of light just by putting a cheap colored transparent sheet, why can't this be the case when the UV light is on topic?
 
  • #4
nasu
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You don't block a wavelength of light but just attenuate some wide bands of wavelengths more than other bands.
If you look at the spectrum of light coming through a colored piece of red (for example) plastic or other cheap colored sheet, you will see that you still have non-zero intensity for yellow and orange and maybe even green and blue.
Same thing is done by your filter, probably.

Filters that can block a very narrow range in visible are also very special and quite expensive.
 
  • #5
sophiecentaur
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Also it's a bit of supply and demand. There are hundreds of photographic filters which pass or block visible wavelengths. Dichroic filters can be very sharp and only mildly expensive. What you have is possibly a rare requirement. Quite doable, I'm sure but on a bespoke basis. The sites all look a bit specialist. I got all enthusiastic when I found "UV filters" but the camera filters all block it.
 
  • #6
sophiecentaur
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It may call for some inventive search terms and perhaps somewhere other than google?
 
  • #7
sophiecentaur
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I found the
Baader Ultraviolet Venus Filter
which may do what you want. It's for UV photography. $400 though, for a 2" circular (camera type) mount.
 
  • #8
Garlic
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I was scrolling through my older posts, when I realized that I have left your effort unthanked.. I am sorry, and thank you. :smile:
 
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