Sigma 24-70mm f/2.8 DG OS HSM ART Lens for Canon EF with USB Dock Bundle

The Sigma 24-70mm F2.8 DG HSM OS Art is a premium workhorse zoom lens designed for the latest high megapixel DSLRs. A constant aperture of 2.8 through the zoom range makes this a highly versatile tool and a brand new Optical Stabilization (OS) system helps compensate for camera shake. Though a common focal length, the Sigma 24-70mm Art brings a new level of usability and durability featuring a rugged metal barrel and an emphasis on image quality. Building off the experience from the 12-24mm Art, the aspherical elements used in the 24-70mm f/2.8 OS Art undergo a highly precise level of polishing, producing elements thicker in the center than on the edges. This process creates stunning image quality and beautiful circular bokeh. Art LensEngineered for those who see photography as an expression of self, Sigma’s Art line offers sophisticated optical performance and abundant expressive power to deliver faithfully on your artistic vision.DG - DG for DigitalSigma's DG lenses are specifically designed to deliver the ultimate level of performance on full frame digital SLRs. Sigma DGs also maximize the abilities of 35mm SLR cameras and APS-C size DSLRs. Thanks to a complete and comprehensive approach to the correction of chromatic aberrations; you will experience incredible image clarity and smoothness. Specific attention was paid to helping eliminate color fringing often caused by lateral chromatic aberration, a problem that is magnified at high resolution in digital photography. DG lenses provide exceptionally high contrast along with subtle gradations in tone and color. The super Multi-Layer coating, along with Sigma's optimized optical design work reduces reflections between the image sensor and the lens surfaces. The large image circles of DG lenses mean there will always be enough peripheral illumination to avoid vignetting.HSM - Quiet and Fast AutofocusingHSM lenses employ a motor powered by ultrasonic waves that produce a quiet, yet high-speed AutoFocus. You can enjoy high performance with low noise in a variety of shooting situations.IF – Inner FocusTo ensure stability in focusing, this lens moves the inner lens group without changing the lens’ physical length.OS - Optical StabilizerThis function utilizes a built-in mechanism that compensates for camera shake. It dramatically expands photographic possibilities by alleviating cameras movement when shooting by hand held camera.Outstanding Optical PerformanceThree SLD (Special Low Dispersion) glass lens elements and four aspherical lens elements minimize optical aberrations. To ensure outstanding edge-to-edge image quality, the optical system minimizes coma, which causes points of light to streak, and transverse chromatic aberration, which cannot be corrected via aperture control. The optical system also minimizes distortion, which can be especially prominent in wide-angle shots.Bokeh That’s a Cut AboveAt wide-open aperture, this lens offers outstanding photographic expression. The area in focus is extremely sharp, while the background exhibits a beautiful bokeh effect with only slight spherical aberration. Since large-diameter zoom lenses are often used at wide-open aperture, SIGMA has paid close attention to the shape of the bokeh, aiming for perfect circularity. Perfect for capturing every moment..