These versatile filters are designed to enhance skin tones and are also perfect for outdoor shooting, improving foliage and earth tones in overcast weather or in shade on a sunny day. The filter adds warmth to skin tones and is ideal for portraits. It absorbs the blue cast caused by certain light sources, and can often be used in combination with other filters, such as colour graduated filters, for landscapes. It is sometimes used as a warmer alternative to a UV filter. Available in densities 1, 2 and 3. The filter is also available in 100x144 mm, 144 mm, 127 mm and 168 mm sizes. Formatt-Hitech glass filters are manufactured from the world's finest optical glass, Schott Superwite.