What's a good Woods Lamp (blacklight) filter gel for a general use lamp?

lectraplayer

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While I understand that best results will be to use a dedicated UV 365 or 395 nM LED flashlight, there are plenty of times when I would like to just carry a filter for one of my general use white lamps for one reason or another. Most of my lamps are various LED models, though I also have a 17 watt HID flashlight, which seems to put out a LOT of UV, causing prominent fluorescence even if I use the yellow filter. What is the best color, or type of gel that I can put over the lens to accentuate the fluorescence of the general use, broad spectrum emitters of many of my lights when I don't want to carry my UV lamps, or they aren't strong enough to cut it?
 

LEDphile

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I'm not aware of any currently or formerly commercially available white LEDs that put out any significant emission below 400nm, so filtering out the visible light isn't going to leave you with anything useful.

For your HID source, you'll need a proper glass UV-pass filter ("Wood's glass"). The optically clear plastics generally block UV (in addition to being degraded by UV and likely not withstanding the heat of an HID fixture), and since that's a function of the plastic substrate, there aren't any additives that can be used at manufacture time to make them into UV-pass filters.
 

PhotonWrangler

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There are also dichroic interference filters that are made to pass UV and block visible light. I have one on an Ultrafire flashlight fitted with a 365nm drop-in. The lens color is silver when it's off. Works pretty well. I found it at B&H.

dichroic_UV_pass_filter.jpg
 

lectraplayer

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Jan 31, 2014
Messages
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I'm not aware of any currently or formerly commercially available white LEDs that put out any significant emission below 400nm, so filtering out the visible light isn't going to leave you with anything useful.

For your HID source, you'll need a proper glass UV-pass filter ("Wood's glass"). The optically clear plastics generally block UV (in addition to being degraded by UV and likely not withstanding the heat of an HID fixture), and since that's a function of the plastic substrate, there aren't any additives that can be used at manufacture time to make them into UV-pass filters.
I'm guessing the blue lens that comes with many lights would likely be as good as I can get for making things fluoresce?
There are also dichroic interference filters that are made to pass UV and block visible light. I have one on an Ultrafire flashlight fitted with a 365nm drop-in. The lens color is silver when it's off. Works pretty well. I found it at B&H.

View attachment 45876
While those look neat, the only thing I see at BH Photo is a $5000 photo/video light. I'll be looking for those elsewhere, though.
 
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