Sigma AF 4.5mm f/2.8 EX DC Circular Fisheye HSM
Sigma AF 4.5mm f/2.8 EX DC Circular Fisheye HSM is a auto focus fisheye lens for aps-c cameras.
It is a ring-type ultrasonic motor designed to provide quick and silent focusing. Has 6 aperture blades, this number of blades are commonly used. Having rounded blades provides out of focus circle shape closer to a circle. Bright lens thanks to the high aperture value Full frame equivalent focal length is 6.75 mm.
Weights 470 grams so plan ahead, carry only if really necessary. 78 mm long, requires consideration if you want to carry in the camera bag.