Polarizing filters, are color neutral and increase picture taking possibilities with black and white or color film. In color photography, unlike black and white photography, there is no possibility to change contrast or color saturation with colored filters. To do so would also change the colors in the photograph. Natural light spreads in a wave form in all direction. Sunlight is polarized and has a high color purity. When passing through the atmosphere a part of it is scattered, which results in a blush gray haze over all colors. This effect can be reduced or eliminated by using polarizing filters. If, in addition, light falls at an angle of approximately 35 Degree onto a reflecting surface, e g. water, glass, plastic, color surfaces, with the exception of metallic surfaces, the light becomes reflected and polarized. If one uses a properly orientated polarizing filter, the reflections are absorbed and the true colors can reach the film. Water surfaces become transparent and clouds are more saturated.The light loss of a polarizing filter varies between 1 and 1.5 F stops which, depending on camera type, can be manually or automatically corrected. HELIOPAN polarizing filters consist of a neutral color foil cemented between two plane parallel glass discs. The foil is constructed so that light rays can only pass in one plane. The polarizing filter is mounted in a calibrated rotating ring so the desired position and effect can be easily set. With an SLR one sees the result

• Extremely thin rim of only 5mm! This eliminates the possibility of vignetting when using wide angle lenses or zoom lenses at their wide angle setting (This filter has no front filter threads)