Canon PL-C 52 (WII) Drop-in Circular Polarising Filter II for Mark II 300mm, 400mm, 500mm, 600mm lenses
Circular polarising filter for certain Canon super-telephoto lenses (Mark II telephoto primes). Polarizing filters enhance picture quality by blocking harmful reflected light. Use it to reduce light reflections from glass and water surfaces or to improve colour saturation. Simple to use, these filters polarize light circularly, rather than linearly, so they do not interfere with autofocus or TTL light metering.