Especially at the sea and in the mountains strong UV-rays appear which clutter the image, cause unsharpness and make colors whitish. The color-neutral UV-filter keeps out these rays, makes the image sharper, brings more contrast and is a price-reasonable lens protection. HTMC term means "High Transmission Multi Coating". Filters and lenses are coated with 4 layers on each side, which facilitates an extremely soft transmission of the light (air-glass-air). Reflections in the optical system of your camera are avoided. Result: image sharpness, contrast and color saturation are improved accordingly. Filters are made of high-quality lens glass.