The ROKINON 24mm F1.4 - RK24M-E Ultra Wide Angle. It's 13 elements in 12 group design utilizes 4 Extra Low-Dispersion (ED) glass elements and 2 Aspherical elements to produce sharply defined images even in low lighting conditions. Focus can be as close as 9.84" for outstanding wide-angle close-up views. Ideal for landscapes, interiors, street photography, low-light photography, and astrophotography. Constructed with 2 Aspherical and 4 ED elements for outstanding, sharply defined images. UMC coating reduces flare and ghosting while increasing contrast. Non-rotating 77mm filter mount.