What photographers demand from the 24-70mm F2.8 specification is much more than outstanding image quality. They want all the features that make this a go-to lens for a wide range of photographic opportunities, including optical design ideal for the latest ultra-high-megapixel digital cameras, hypersonic motor (HSM) for high-speed autofocus, optical stabilizer (OS) with powerful stabilization effect, dust- and splash-proof mount with rubber sealing, and a metal barrel for a stable, rigid feel. This all-new 24-70mm F2.8 lens from SIGMA delivers the performance and functionality that help pros succeed in news, nature, and many other fields of photography.
Outstanding optical performance
Three SLD glass lens elements and four aspherical lens elements help minimize optical aberrations. To ensure outstanding image quality from the center to the edges of the photograph, the optical system minimizes coma, which causes points of light to streak, and transverse chromatic aberration, which cannot be corrected by adjusting the aperture. The optical system also minimizes distortion, which can be particularly evident in wide-angle shots, resulting in excellent optical performance throughout the zoom range.
Bokeh that is a cut above
At 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.
Exclusive low-dispersion glass
The degree to which light is refracted by glass depends on the light's wavelength. This fact causes different colors of light to focus at slightly different points. The result is chromatic aberration, the color fringing that is particularly noticeable in telephoto lenses. Most chromatic aberration can be removed by combining a high-refractivity convex lens element with a low-refractivity concave element. Yet residual chromatic aberration known as "secondary spectrum may still remain. To minimize this secondary spectrum, which can be a serious issue with conventional lenses, SIGMA lenses feature up to three types of exclusive low-dispersion glass offering superior performance: ELD (Extraordinary Low Dispersion), SLD (Special Low Dispersion) and FLD ("F Low Dispersion). In particular, FLD glass offers ultra-low dispersion in combination with high transmittance and the anomalous dispersion characteristics of fluorite.
Designed to minimize flare and ghosting
From the start of the design process, SIGMA measured flare and ghosting to establish an optical design that is resistant to strong incidental light sources such as backlight. SIGMAs Super Multi-Layer Coating helps further reduce flare and ghosting and provide sharp, high-contrast images even in backlit conditions.
Incorporating the OS function for success on any shoot
Designed for advanced utility in a wide variety of situations, the optical stabilizer (OS) offers a powerful stabilization effect.
Newly designed HSM for fast AF performance
The newly designed hypersonic motor (HSM) offers 1.3 times the torque of its predecessor. Even at low speeds, it offers exceptionally stable performance.
Fast AF with full-time manual focus
Full-time manual focus function allows the lens to be switched to manual focus simply by rotating the focus ring.
Rounded diaphragm
The 9-blade rounded diaphragm creates an attractive blur in the out-of-focus areas of the image.
Mount with dust- and splash-proof design
Since the area of the lens most vulnerable to dust and other foreign bodies is the mount, rubber sealing helps provide peace of mind. In addition, the front lens element features a water- and oil-repellant coating that helps the lens perform well in the rain, near water, and in other challenging conditions.
High-precision, rugged brass bayonet mount
The brass mount combines high precision with rugged construction. Its treated surfaces and enhanced strength contribute to the exceptional durability of the lens.
Specifications
Lens Construction: 19 Elements in 14 Groups
Angle of View (for SD1): 84.1 -34.3 degrees
Number of Diaphragm Blades: 9 (Rounded diaphragm)
Minimum Aperture: F22
Minimum Focusing Distance: 37cm / 15.0in.
Maximum Magnification: 1:4.8
Filter Size: Diameter 82mm
Dimensions: Diameter 88mm x Length 107.6mm / 3.5in. x 4.2in.
Weight: 1,020g / 36 oz
