The Heliopan Bay 104 Skylight KR 1.5 (1A) Filter is a general use filter with a slight pink tint to help improve overall color accuracy and clarity. The light pink coloration helps to reduce the overall bluish cast of daylight and is especially effective when photographing landscapes and in shade. The Skylight 1A filter is also useful as a general protective filter to leave on lenses at all times. Filters help to reduce dust and moisture from reaching your lens element and provide additional protection in case of drops or situations where scratching could occur. This filter features a brass mounting ring that is painted matte black to help reduce reflections. High quality Schott glass provides optical clarity and greater contrast to help render scenes with greater fidelity and resolution. The Bay 104 mount is compatible with lenses featuring a bayonet filter mount, such as those made by Hasselblad and Rollei.