This ultra-wide-angle lens has the shortest focal length in the L-series.
Element 2 is an aspherical lens to correct distortion.
Other aberrations such as astigmatism are also corrected, resulting in idea image quality.
Lens construction: 14 elements in 11 groups
Diagonal angle of view: 114°
Focus adjustment: Rear focusing system with USM
Closest focusing distance: 0.20m / 0.8ft
Filter size: Rear drop-in gelatin filter holder