Nano Crystal coating system (n's) for increased light transmission and reduced internal Reflections

Maximum diameter: 3. 43 inches (87mm). fast F28 maximum aperture + close-focusing to 95 inches = maximum versatility in all shooting conditions

Optimized for excellent optical quality and true ultra-wide 106 Degree edge to edge coverage with Canon APS-C sensor digital cameras

Utilizes 3 high precision (2 aspherical + 1 ED) Lens elements for superior image quality

Inner focusing system (if) – length doesn't change and front element does not rotate – keeps integrated petal-type lens hood properly oriented