Canon
PL-C 52WII
52mm Drop-In Circular Polarizing Filter
The 52mm PL-C 52WII Drop-in Circular Polarizer from Canon is designed to enhance your picture quality by blocking reflected light from glass and water surfaces for improved colour saturation. Simple to use, it polarizes light circularly, rather than linearly, so it will not interfere with autofocus or TTL light metering.
It is designed for use with the Canon EF 300mm f/2.8L IS II USM and EF 400mm f/2.8L IS II USM lenses, which accept rear-mounted drop-in filters. The glass is secured within a strong metal frame that slips in and out of the rear mount with ease. The degree of polarization can be seen through the viewfinder of your camera as you rotate the filter.