Reduces glare and enhances color by selectively cancelling the amount of reflected polarized lightwaves caused by a wide variety of objects, such as glass from buildings, cars and vessels, the sky and clouds, foliage, precious gems, pavement, sand, snow and water. In landscape photography, a CPL can piercehaze revealing dramatic vistas, increase tone and color vibrancy plus give the illusion of depth. By carefully rotating the rings of the filter, you can observe the cancellation effect in the viewfinder tothe degree that you desire. The filter has no effect on metallic substances as they do not reflect polarized light and little effect on flash as the light source must be polarized as well. The Filter Factor varies from 1.25x to 2x depending on the strength of effect.