Samyang MK2 14mm f/2.8 Weather Sealed Ultra Wide Angle Lens for Canon EF #MK14-C. In addition, the focusing control action has been modified with a smoother, perfectly damped long throw for precise follow focus when shooting video. Astrophotographers will also enjoy the 14mm’s distinctive focus lock feature to maintain precise focus at infinity during long exposures. Optically constructed of 14 elements in 10 groups (1 Asperical, 1 Hybrid Asperical, 2 ED, 3 High Refractive). Built-in lens hood and a soft lens pouch is included. Features ultra multi-coated glass and 9 aperture blades. Angle of view of 115.7 degrees on full frame and 89.9 degrees on APS-C. Aperture Rangef/2.8 – f/22Optical Construction14 Elements in 10 GroupsSpecial lensASP 1, Hybrid ASP 1, ED 2, HR 3CoatingUMCMinimum Focusing Distance0.92′ (0.28m)Magnification Ratiox0.08Diaphragm Blades9Maximum Diameter87mmMountCanon EFAngle of viewFull Frame: 115.7 Degree. APS-C: 89.9 DegreeLength3.78 (96.1mm)Weight24.4 oz (649g).