Mudcat Café message #2902567 The Mudcat Café TM
Thread #129314   Message #2902567
Posted By: s&r
08-May-10 - 05:23 AM
Thread Name: BS: COLORED Shadow?
Subject: RE: BS: COLORED Shadow?
Sodium vapour lamps have a well defined and discontinuous spectrum. This gives strange effects. Commonly for example red lipstick under a (yellow) sodium lam looks black. This is because there is no common hue that the red lipstick can reflect.

A yellow lamp from a (say) tungsten source has a range of frequencies present from red through blue with a peak in the yellow area. Rhe red component of the light is reflected by the lipstic and show red.

Fluorescent lamps hav a dscontinuous spectrum, and often a 'daylight ' fluorescent lamp will produce a green cast on a photograph.

Stu