FeaturesCompatible with Nikon F mountOptical Stabilisation system4 FLD (F Low Dispersion) glass elementsHigh ratio zoom lens1 SLD (Special Low Dispersion) glass elementA high ratio zoom lens often requires compactness and enhancement of additional features, to be capable enough to cover various shooting scenes with convenience and versatility. However, SIGMA still believes that image quality is what matters the most. When travelling with minimal equipment the lens needs a wide zoom range especially as a telephoto lens may be needed unexpectedly without time to switch lenses. Even with a high ratio zoom lens, our goal is to satisfy enthusiastic photographers with the versatility of the lens and its optical performance. This Sigma 18-300mm f/3.5-6.3 DC Macro HSM Contemporary Zoom Lens for Nikon F Mount is good either as your first interchangeable lens or as a high performance all in one lens.Excellent optical performance that satisfies experienced usersThis lens incorporates 4 FLD (F Low Dispersion) glass elements, which have performance equal to fluorite plus 1 SLD (Special Low Dispersion) glass element. It enables this lens to minimize the chromatic aberration, especially toward the telephoto-end, and provide clear image quality with high colour fidelity* FLD glass is the highest level low dispersion glass available with extremely high light transmission. This optical glass has a performance equal to fluorite glass which has a low refractive index and low dispersion compared to current optical glass. It also benefits from high anomalous dispersion. These characteristics give excellent correction for residual chromatic aberration (secondary spectrum) which cannot be corrected by the ordinary optical glass and ensures high definition and high contrast images. Renewed OS system for higher compensationBy reviewing the system construction and the algorithm of firmware, 3.5 steps compensation has been achieved. * Based on CIPAs guideline. Measuring at the telephoto end, when it is attached to the camera with an APS-C image sensor. * The lenses for SONY and PENTAX do not incorporate the OS function. Zoom-macro for enhanced macro photographyJust by rotating the zoom ring, it enables photographers to take close-up pictures of subjects such as jewellery and flowers. The maximum magnification ratio at respective focal lengths is indicated on the lens barrel, thus it is easy to see what the object size will be at the sensor. Furthermore, in order to secure a clear field of view, the design of this lens is very thorough, even down to the precise position of the engraved letters on the lens. Newly Developed Hyper Sonic MotorFor comfortable and smooth use with the high zoom ratio, 16.6 times, it incorporates a bigger HSM (Hyper Sonic Motor) which is newly developed for this lens. It is powerful enough to ensure high speed and quiet AF. * For Pentax mount, if the camera body does not support HSM, autofocus will not be available. Designed to minimize flare and ghostingFlare and ghosting were thoroughly measured and 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 and ghosting and provides sharp and high contrast images even in backlit conditions. Incorporating Rounded DiaphragmThe 7 blade-rounded diaphragm creates an attractive blur to the out-of-focus areas of the image. SpecificationsLens Construction: 17 Elements in 13 GroupsThe angle of View (for SD1): 76.5 - 5.4 degreesNumber of Diaphragm Blades: 7 Blades(Rounded Diaphragm) Minimum Aperture: F22Minimum Focusing Distance: 39cm / 15.4in. Maximum Magnification: 1:3Filter Size: 72mmDimensions: 79mm x 101.5mm / 3.1in. x 4.0in. Weight: 585g/20.6oz.