Recently, DSLR cameras have been evolving rapidly, and more and more photographers have been seeking a lens that can bring out the potential of a high-resolution sensor. There are occasions when photographers select zoom lenses as they offer more convenience than a fixed focal length lens, yet they do not want to compromise on image quality. SIGMA has long tackled this task to provide excellent quality images for such occasions. We are proud that SIGMA 24-105mm F4 DG OS HSM meets these requirements and is the standard zoom lens from our “Art” line, offering stable and fine image quality from wide to mid-telephoto range. It has a combination of fixed aperture and a good zoom ratio that we kept as high as possible. Many simulations were carried out before achieving this goal, and made the specification compatible with 35mm full size image sensors. Moreover, it was designed to surpass the quality inspection of the original MTF measuring system, A1, so it has succeeded in creating superior image quality for new standard of high-spec cameras. This lens incorporates the OS function and minimizes camera shake effectively.