The Sigma 17-70mm f/2.8-4 DC Macro OS HSM is a Contemporary-series lens, also characterized by its compact, lightweight profile. The bright f/2.8-4 maximum aperture range pairs with the wide-angle to short-telephoto zoom range to create an ideal travel and everyday lens. The optical design uses a series of low dispersion and aspherical elements to control color fringing and distortion in order to realize high clarity and sharpness. A Super Multi-Layer Coating has also been applied to suppress flare and surface reflections for improved contrast in bright conditions.