Product description the sigma 24 70mm f28 ex dg benefits from eld extraordinary low dispersion glass two sld special low dispersion glass elements and a molded glass aspherical lens to provide excellent correction for all types of aberrations high image quality is assured throughout the entire zoom range the lens has a compact construction with an overall length of 947mm 37rdquo it is ideal for many situations such as portrait landscape and general photography this lens offers a large ap