Filter factor is approx. This colorless ultraviolet absorbing filter is used to eliminate haze from ultraviolet rays and possible fluorescence from the lens cement. Used for high-altitude photography. Filter factor is approx. Due to the slight yellow coloring of this filter, it is designed for aerial photography with black and white film.
Filter factor is approx.
This filter is used to differentiate reproductions of green tones in reproduction photography. It may also be used to create the effect of haze. Filter factor is approx. It is especially recommended for CCD applications where digital image sensors have not been fitted with an IR protection filter. Although this dark-violet filter transmits a small amount of visible light, it completely blocks wavelengths longer than 360nm.