The Sigma 24-105mm f/4 DG OS HSM is an Art-series zoom covering a useful wide-angle to short-telephoto range. Featuring a constant f/4 maximum aperture, this lens strikes an ideal balance between a portable form factor along with a bright enough design for working in available lighting conditions. Complementing this design, an Optical Stabilizer helps to minimize the appearance of camera shake throughout the zoom range for sharper handheld shooting.