The Tiffen 77mm UV Protector Filter is a general use, clear filter that helps to absorb ultraviolet light and reduce the bluish cast of daylight. This filter is especially useful when photographing at high altitudes or around bodies of water. No additional coloration or contrast is provided, allowing you to pair this filter with others. The UV 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 Color Core technology; a process that involves laminating the filter substrate between 2 pieces of optical glass, grinding flat to a tolerance of 1/10,000th of an inch, then mounting to precision metal rings. Absorbs some ultraviolet light and reduces bluish cast of daylight. Clear filter provides no additional coloration or contrast, allowing you to pair this filter with others. General protection filter reduces dust, moisture, and scratches from reaching lens elements.