Zoom lenses are very convenient. The equivalent of two or more fixed focal length lenses in one unit. The maximum aperture of some zoom lenses changes as you alter the focal length, but through-the-lens (TTL) metering takes this into account to give correct exposure.

This high performance telephoto zoom lens EF 70-200MM 1:4 L USM provides excellent performance for all general purposes. The compactness and light weight make it an excellent travel companion.

High-performance, L-series telephoto zoom lens combining light weight and compactness with an f/4 maximum aperture. Inner focusing and the ring USM enable quick and quiet autofocusing. Also, a circular polarizing filter can be attached and used without difficulty because the front lens element does not rotate during focusing. The tripod collar (sold separately) is the same one used with the EF 300mm f/4L USM.

Features
Lens construction: 16 elements in 13 groups
Diagonal angle of view: 34°-12°
Focus adjustment: USM
Closest focusing distance: 1.2m
Filter size: 67mm