The lens features a total of 18 elements in 15 groups, with three aspherical and five Special Low Dispersion elements to minimize flare and ghosting and suppress various aberrations. This results in an optical performance that meets or exceeds that of other Sigma Art lenses, including the primes. Along with its 11-blade, rounded diaphragm, the design promotes sharpness and a large, smooth bokeh when used wide open.
In addition to the f/1.8 maximum aperture, the lens also maintains an 11.9″ minimum focusing distance across the entire zoom range. It achieves a maximum magnification ratio of 1:4 at its longest focal length, increasing depth of field and versatility in tight spaces.
