The Sky 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.
Tiffen filters are made using ColorCore technology; a process that involves laminating the filter substrate between 2 pieces of optical glass and grinding flat to a tolerance of 1/10,000th of an inch. This filter measures 4 x 4" / 101.6 x 101.6mm.
Made in the USA!