Telephoto zoom lens series canon ef canon l lens mount canon ef lens speed 4 focal length 200 400 mm suitable for sensor types aps c full frame construction zoom lens area of use sports photography animal photography image stabiliser focus auto focus manual focus af motor ultrasonic motor usm circular aperture closest focusing distance 200 cm lens construction groupselements 2025 number of aperture blades 9 minimum aperture 32 max apertur