Crystal Optics 86mm Circular Polarizer Filter

This was the second CPL I purchased for use on a sigma 150-500mm lens mounted on a Nikon D7000. This filter does not permit the the lens to focus. This was my second attempt at purchasing an inexpensive filter and as the saying goes...you get what you...

This was the second CPL I purchased for use on a sigma 150-500mm lens mounted on a Nikon D7000. This filter does not permit the the lens to focus. This was my second attempt at purchasing an inexpensive filter and as the saying goes...you get what you...