UVC Purification Lamps / HNS Germicidal lamps

[Tebbe Schoeningh]

Hi all,

 

I´m gonna be shooting in a slaughterhouse and I noticed that they are using special HNS lamps to desinfect the ambience.

 

Aparently those lights are working with an extended UV-spectrum and they look really magenta.

 

Does anyone know if there are special UV-Cut filters to use in camera for this occasions?

 

Thanks in advance

 

Tebbe

[Michael E Brown]

Hi all,

 

I´m gonna be shooting in a slaughterhouse and I noticed that they are using special HNS lamps to desinfect the ambience.

 

Aparently those lights are working with an extended UV-spectrum and they look really magenta.

 

Does anyone know if there are special UV-Cut filters to use in camera for this occasions?

 

Thanks in advance

 

Tebbe

 

Schneider has a UV-410 filter that cuts rays below 410 nm. Looking at the spec sheet for Osram's HNS lamps, they put out UVC at 254 nm and in some versions at 185 nm also.

 

Something to be careful of perhaps is using wide angle lenses with real UV cut filters that have a special coating (as opposed to just clear glass, which also cuts some UV by nature). Apparently with lenses over 60 degrees FOV, the edge rays pass thought the filter at a different enough angle from the center rays to cause a blue shift on the edges. Probably similar to the effect of shining a light through a dichroic glass filter - the color will shift depending on the angle of the rays striking the coating. With a blue dichroic, rays that hit the coating at a 45 degree angle shift towards purple.

 

What format are you shooting? If all the lights are this same type, you may be able to white balance the magenta cast out.

Edited September 29, 2010 by Michael E Brown

[John Sprung]

This is the kind of thing that really demands shooting tests, not theory.

 

 

 

 

-- J.S.