As entry level lenses for digital SLR cameras, standard zoom lenses are capable of many types of photography. With this lens, you can enjoy the variation of different angle-of-views covering from a wide-angle of 18mm (equivalent to 27mm on a 35mm camera) to a telephoto of 200mm (equivalent to 300mm on a 35mm camera), as well as Macro. Moreover, thanks to the OS (Optical Stabilizer) functionality, while pursuing convenience of handheld photography for close-up, indoor & night time photography, SIGMA incorporated the latest technology freely in order to achieve its compact size as an everyday lens. SIGMA proposes a new standard zoom lens. Diameter reduced by 4.6mm compared to its predecessor We pursued the compactness as an ideal everyday lens. From an early stage of development, SIGMA was determined to make the lens size compact, for example, by incorporating double-sided aspherical lens elements & downsizing the motor. As a result, while the predecessor had a diameter of 75.3mm, this lens has reduced it to 70.7mm, which has the difference of 4.6mm. It also achieves -11% in volume ratio compared to its predecessor. It is one of the smallest in its class of lenses with more than a 7x zoom ratio, & is more comparable in size to a generic standard zoom lenses. High rendering performance throughout the entire zoom range With our Contemporary line, the lens is required to fulfill the maximum potential while achieving a compact & light-weight construction. This lens incorporates SLD (Special Low Dispersion) glass elements that have a high refractive index, & corrects chromatic aberration at the telephoto-end very well. Moreover, aspherical lens elements, including double-sided aspherical lenses, ensure a compact size & excellent correction of distortion. This also helps to produce superior rendering performance throughout the entire zoom range from wide-angle to tele-photo & macro photography. Close-up photography One of the biggest features of this lens is that it is possible to shoot subjects as close as macro lenses. This lens features a minimum focusing distance of 39cm & a maximum magnification ratio of 1:3. It offers the versatility for shooting close-ups of fashion accessories, cuisine, flower arrangements & much more without changing the lens. Its working distance is 14.7cm, & it is suitable for shooing images with natural light as it keeps the shadows of camera & lens off of the image. 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. Designed to minimize flare & ghosting Flare & ghosting were thoroughly measured & monitored from the lens development stage 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. Incorporating Rounded Diaphragm The 7 blade-rounded diaphragm creates an attractive blur to the out-of-focus areas of the image. Hyper Sonic Motor HSM (Hyper Sonic Motor) delivers high AF speed & extremely quiet performance. With the latest AF algorithm, smoother AF is achieved. * For Pentax mount, if the camera body does not support HSM, auto focus will not be available Brass made bayonet mount This lens incorporates a brass made bayonet mount which has both high accuracy & durability. A special treatment to reinforce its strength is applied to the surface giving it greater strength & making it highly resistant to long-term use.