This is a Samyang lens that comes with auto focus to give you the best setting for each picture. As for the lens type, this is a standard lens.
From WEX Photo Video
Samyang VDSLR 50mm T1.5 MK2 Lens for Nikon F
Camera Centre
Samyang 50mm T1.5 VDSLR MK2 Lens - Nikon F Mount