Super telephoto zoom lens series walimex pro lens mount sigma sa lens speed 8 focal length 650 1 300 mm zoom factor 2 times suitable for sensor type aps c construction zoom lens area of use astrophotography animal photography focus manual focus internal focus af motor no internal af motor closest focusing distance 500 cm lens type aspherical lens construction groupselements 58 number of aperture blades 7 minimum aperture 16 max aperture 8