Sigma 17-50mm f/2.8 EX DC HSM

Sigma 17-50mm f/2.8 EX DC HSM is a auto focus prime zoom lens for aps-c cameras.

Optical design

Has 7 aperture blades, mid-grade lenses usually have this amount of blades. Having rounded blades provides out of focus circle shape closer to a circle. Full frame equivalent focal length is 25.5-75.0 mm. It is a ring-type ultrasonic motor designed to provide quick and silent focusing. Bright lens thanks to the high aperture value

Physical characteristics

With a lens filter diameter of 77 mm this lens deserves a good quality filter, this is commonly filter size, gives you a variety of filter options. Weights 565 grams so plan ahead, carry only if really necessary. 92 mm long, requires consideration if you want to carry in the camera bag.