Overview of the Urth Circular Polarizing Lens Filter Plus+ (105mm) The Urth Circular Polarizing Lens Filter Plus+ cuts polarized light to increase contrast and boost color saturation and vibrancy by filtering out reflections from water, sky, glass, and non-metallic surfaces. A polarizing filter is an essential tool for landscape photography, as it saturates a blue sky to make clouds pop and reveals details under the surface of water obscured by glare. Urth Plus+ filters feature 20 layers of nano-coating to provide easier cleaning and better protection against water, oil, and scratches. The nano-coating layers also provide a higher maximum light transmission and a more consistent transmission curve for sharper images and finer color transmission. This filter is made with Shott B270 optical glass mounted in an ultra-slim, rotating magnalium alloy filter ring. The slim design prevents vignetting when used with wide-angle lenses, while maintaining lightweight durability.