SIGMA 1835mm F1.8 DC HSM What makes a standard lens ideal for you Certain important qualities are required such as fast maximum aperture versatility for snap shots portraiture and indoor photography plus a good combination of a wide range of focal lengths in a compact design. SIGMA 1835mm F1.8 DC HSM is the first zoom lens ever to achieve a maximum aperture of f1.8 throughout the zoom range. It is a wide aperture standard zoomlens for digital single lens reflex cameras with APSC size sensors. 1 The lens has a focal range equivalent to 27mmnbsp 52.5mm in a 35mm format and it can cover the angles of view of multiple fixed focal length lenses. This wide aperture standard zoom lens enables the photographer to expand creative possibilities on any occasion. 1nbsp As of April 2013 Sigmas Art line delivers highlevel artistic quality. Sigma is organizing all its interchangeable lenses into three product lines Contemporary Art and Sports. Designed with a focus on sophisticated optical performance and abundant expressive power thenbspArt line delivers highlevel artistic expression. Developed with the maximum emphasis on artistic touch they are designed to meet the expectations of users who value a creative dramatic outcome above compactness and multifunction. Along with landscapes portraits stilllife closeup and casual snaps they are perfect for the kind of photography that unleashes the inner artist. Ideal for studio photography they offer just as much expressive scope when capturing architecture starry skies underwater shots and many other scenes. Excellent Usability. A zoom lens is very convenient as it offers various angles of view just by rotating the zoom ring. However the down side was that no zoom lens ever offered a faster aperture than f2.8 which led photographers to select fixed focal length lenses for brighter images. While the aperture value of prime lenses is superior to zoom lenses their field of view is always the same and therefore it was always necessary to carry many fixed focal length lenses. SIGMA 1835mm F1.8 DC HSM isnbspa next generationnbsplens that can deliver images at f1.8 aperture throughout its focal length. The bright viewfinder is very helpful for checking the focus and composition of the image. If it is compared with a lens of F2.8 the faster shutter speed and the shallow depth of field of F1.8 further expands creativity. From wide to standard range this lens offers the excellent versatility and performance of multiplefixed focal length lenses. Fruit of cutting edge technology. To achieve a wide zoom lens with a maximum aperture of f1.8 various technical problems need to be overcome. As the aperture value gets larger the depth of focus becomes shallower thus it makes the lens design extremely complicated in order to compensate for various distortions such as spherical axial chromatic and astigmatic aberration along with curvature of field. In order to compensate for astigmatic aberration across the entire focal range Sigma has relied on the experience and know how gained when designingnbsptheir super wide angle zoom lenses such as SIGMA1224mm F4.55.6 II DG HSM and SIGMA 816mm F4.55.6 DC HSM. In addition the technological innovation at our Aizu factory also contributes to better lens production. It has enabledSigmanbspto develop a wide glassmolded aspheric lens and the incorporation of SLD Special Low Dispersion glass has optimized power distribution of the optical elements and compensated for various aberrations as well as curvature of field at the widest angle. Thanks tonbsptheir knowledge of lens design accumulated over a long period of time plus the latest lens manufacturing techniques SIGMA has finally made the dream of a zoom lens with F1.8 throughout its entire focal range come true. Convenient handling. Convenient handling is achieved by incorporating internal focusing and zooming which prevents any change in the length of the lens when focusing and zooming. It is possible to use a specialist filter such as a Circular Polarizer as the front part of the lens does not rotate. Designed to minimize flare and ghosting. Flare and ghosting were thoroughly measured and 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 MultiLayer Coating reduces flare and ghosting and provides sharp and high contrast images even in backlit conditions. Attaching the matched petal type hood which is suppliedwill provide extra protection from flare and ghosting. Minimum focusing distance of 28cm. With a minimum focusing distance of 28cm and a maximum magnification ratio of 14.3 this lens is excellent for closeup photography. Hyper Sonic Motor. The HSM Hyper Sonic Motor ensures a silent highspeed AF function. Optimizing AF algorithm smoother AF is achieved. It also enables fulltime manual focusing capability which