Recently, DSLR cameras have been evolving rapidly, & more & 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 & is the standard zoom lens from our " Art" line, offering stable & fine image quality from wide to mid-telephoto range. It has a combination of fixed aperture & a good zoom ratio that we kept as high as possible. This lens incorporates the OS function & minimizes camera shake effectively. Covering the standard shooting range of 35mm full size image sensor The convenience of a zoom lens enables photographers to capture various subjects without the need to change lenses. The SIGMA 24-105mm F4 DG OS HSM is a very handy zoom lens that covers the basic shooting range from wide to mid-telephoto. Moreover, its constant aperture of F4, OS (Optical Stabilizer) & HSM (Hyper Sonic Motor) enhances the lens usability. It is ideal for portraits, landscapes & general photography. Superior image quality This is a lens that represents the concept of our Art line, & it meets the highest standard of our quality test. For those standard lenses with a high zoom ratio, they tend to show astigmatic aberration, field curvature, distortions & color aberration. In order to compensate for these, various types of high-performance lenses, such as FLD, SLD & glass-molded aspheric lenses including double-sided aspheric lens, have been included into the optical system. In addition, it suppresses chromatic aberration very effectively at telephoto-end, & achieves superior image quality throughout the zoom range. This lens overcomes low peripheral brightness that is common for those lenses with similar specifications. Also, the wide filter size 82mm is contributing for superior optical performance. Optical Stabilizer This lens incorporates an OS system which offers superior stabilization, making it possible to compensate for camera shake even in macro range photography where a small blur can be easily identified. * This lens cannot be used with film SLR cameras with the exception of the Nikon F6, Canon EOS-1v. * For Sony, OS function is not incorporated. Convenient handling The lens wide zoom ring ensures convenient handling. By putting the zoom ring in front, allows the lens barrel to be more compact. The inner focusing system eliminates front lens rotation, enhancing the lens stability & allowing use of Circular Polarizing filters. Designed to minimize flare & ghosting Flare & ghosting were thoroughly measured & monitored from an early stage in the lenses development to establish an optical design which is resistant to strong incidental light such as backlight. The Super Multi-Layer Coating reduces flare & ghosting & provides sharp & high contrast images even in backlit conditions. Attaching the matched petal type hood, which is supplied, will provide extra protection from flare & ghosting. Minimum focusing distance of 45cm With a minimum focusing distance of 45cm & a maximum magnification ratio of 1:4.6, this lens is excellent for close-up photography. Hyper Sonic Motor The HSM (Hyper Sonic Motor) ensures a silent, high-speed AF function. Optimizing AF algorithm, smoother AF is achieved. It also enables full-time manual focusing capability which allows sensible focus adjustment by simply rotating the focus ring. Incorporating Rounded Diaphragm The 9 blade rounded diaphragm creates an attractive round bokeh at large-aperture settings. Design concept The new product lines incorporate rubber for the attachment part of the provided lens hood. For better usability, the designs of the lens cap & AF/MF changeover switch have been enhanced. In order to ensure high accuracy of the product, all metallic parts & the new compound material, TSC (Thermally Stable Composite), which has a high affinity to metal parts, are housed internally. On the lens barrel, the last three digits of its release year are engraved so the lens can be identified according to the year of its launch.