Visible Light Pass Filter

I am wondering if there is a filter that blocks visible light only --- and

allows both UV and IR light. If anyone has ever heard of that, I'd appreciate

the info. Thanks

Unfortunately, any filter that blocks visible light and passes infrared also blocks UV. At least that is what my filter catalogs show. I assume that you want to pass image forming light, and not just a general transmission. There are devices which can do this but are completely impractical to add to a camera lens.

John,

I have seen lowpass (UV) I.E blocks everything > 380nm-420nm and highpass (IR) blocks everything < 720nm-1000nm. Also some specialty narrow band filters but I have never seen one that blocks all of and just the visible spectrum.

Since UV and infrared wavelengths are at opposite ends of the visible spectrum, there is no way a filter can block just the visible light wavelengths and let UV and infrared pass through -- you would need to choose one or the either and not both.

My understanding is that many UV bandpass filters have a secondary transmission "lobe" in the near IR. See for example the U-330 transmission curve below:

 

http://www.newportglass.com/hoyu330.htm

 

and

 

http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productID=1924

That's interesting. This filter isn't shown in my Hoya catalog. It sure beats anything like I was thinking about.

thanks edwin-

Indeed the U330 might be just the ticket, a little low on the sensitivity in NIR vs the UV side but depending on the use could be quite appropriate.

 

john - By the way what use are your planning on using this for, courious minds want to know :-)

Mark, I don't have anything special in mind. I'm just an amateur who is interested in light and shadow in photos --- pictures in which the light itself is the subject. I'm always looking for new ways of exploring the field; and this idea of a visible-light filter popped into my mind. So I thought I'd see what you experts know about the subject. Thanks to all for the responses!

I wonder how much of a difference in focus between IR and UV you would run into if you tried using this on your camera, with an ordinary lens.

 

Nikon had a special UV lens made of quartz and fluorite optics which supposedly had minimal chromatic aberrations and would bring most of the recordable spectrum into simultaneous focus. (It wasn't a cheap lens.)