Filters serve several purposes for camera lenses, including protection from dirt and scratches, cutting through atmospheric haze, saturating colors, eliminating glare, and allowing photographers to blur motion or shoot with wider aperture in bright lighting. The main types of filters are UV filters for protection and reducing haze, polarizing filters for making clouds pop out and saturating colors while eliminating glare, and neutral density filters for blurring motion by dropping shutter speed or shooting with wider aperture in bright conditions. Photographers are advised to check their lens size and specifications to ensure proper filter fitting and to consider Tiffen filters.