A high ratio zoom lens often requires compactness & enhancement of additional features, to be capable enough to cover various shooting scenes with convenience & 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 & its optical performance. This lens is good either as your first interchangeable lens or as a high performance all in one lens. Excellent optical performance that satisfies experienced users This 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, & provide clear image quality with high color 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 & 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 ordinary optical glass & ensures high definition & high contrast images. Renewed OS system for higher compensation By reviewing the system construction & the algorithm of firmware, 3.5 steps compensation has been achieved. * Based on CIPAs guideline. Measuring at tele-photo end, when it is attached to the camera with APS-C image sensor. * The lenses for SONY & PENTAX do not incorporate the OS function. Zoom-macro for enhanced macro photography Just by rotating the zoom ring, it enables photographers to take close-up pictures of subjects such as jewelry & flowers. 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 Motor For comfortable & 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 & quiet AF. * For Pentax mount, if the camera body does not support HSM, auto focus will not be available. 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. Incorporating Rounded Diaphragm The 7 blade-rounded diaphragm creates an attractive blur to the out-of-focus areas of the image. Specifications Lens Construction: 17 Elements in 13 Groups Angle of View (for SD1): 76.5
- 5.4 degrees Number of Diaphragm Blades: 7 Blades (Rounded Diaphragm) Minimum Aperture: F22 Minimum Focusing Distance: 39cm / 15.4in. Maximum Magnification: 1:3 Filter
Size: 72mm Dimensions: 79mm x 101.5mm / 3.1in. x 4.0in. Weight: 585g/20.6oz.