This high-performance lens was designed with portability and handling ease in mind.
One super UD-glass element, whose characteristics are similar to fluorite, and one UD-glass element result in sharp pictures from corner-to corner.

Focal length and maximum aperture: 400 mm f5.6
Lens construction: 7 elements in 6 groups
Diagonal angle of view: 6°-10°
Focus adjustment: Inner focusing system with USM
Closest focusing distance: 3.5m / 11.5ft
Filter size: 77mm