EF 600mm f4L USM
The EF 600mm f4.0L is Canon’s first super telephoto EL lens and is aimed primarily at professional photographers for nature, news, and outdoor sports photography.
A built-in USM enables a drive speed of only 0.99 seconds from infinity to closest distances of 6m, and the optical system uses one fluorite and two UD glass elements. These materials and a new optical system design reduce aberration variation with respect to distance and improve picture quality at short shooting distances.
As with the EF 200mm f1.8L, the 600mm f4.0L has an electronic manual focus system and a preset focus memory. Lens construction is 9 elements in 8 groups (including protective glass and 48mm drop-in rear filter) and both lenses also have a tripod mount which can be rotated through 90° for vertical format shots.
Focal length and maximum aperture: 600mm f4