The 28-70mm f/2.8 DG DN Contemporary Lens for Sony E-Mount from Sigma is a versatile wide-angle to portrait-length zoom characterized by its f/2.8 constant maximum aperture. The design suits working in available lighting conditions while affording increased control over the depth of field. More lightweight and compact than similar 24-70mm lenses, its optical design incorporates two FLD and two SLD low-dispersion elements plus three aspherical elements that reduce a variety of aberrations to achieve high sharpness, enhanced clarity, and improved color accuracy.