Sigma 17-70mm f/2.8-4 Three Aspherical Elements DC Macro HSM Contemporary Lens for Sony A

Overview

Mixing a useful zoom range with a sophisticated design, the Sony A-mount Sigma 17-70mm f/2.8-4 DC Macro HSM is a Contemporary-series lens, also characterized by its compact, lightweight profile. The bright f/2.8-4 maximum aperture range pairs with the wide-angle to short-telephoto zoom range to create an ideal travel and everyday lens. The optical design uses a series of low dispersion and aspherical elements to control color fringing and distortion in order to realize high clarity and sharpness. A Super Multi-Layer Coating has also been applied to suppress flare and surface reflections for improved contrast in bright conditions. Also, this zoom sports a high 1:2.8 maximum magnification and 8.7" minimum focusing distance to suit working with close-up subjects. 

• As part of the Contemporary line within Sigma's Global Vision series, this lens is designed to achieve a balance between convenience and performance and meshes a compact, lightweight build and versatile handling with notable optical attributes.
• Wide-angle to short-telephoto zoom is designed for APS-C-format Sony A-mount cameras and provides a 25.5-105mm equivalent focal length range.
• The bright f/2.8-4 maximum aperture range is suitable for working in available light conditions and also benefits depth of field control for isolating subject matter.
• One Special Low Dispersion (SLD) and two F Low Dispersion (FLD) elements are featured in the optical design and help to reduce color fringing and chromatic aberrations for improved clarity and color accuracy.
• Three aspherical elements are used to help limit distortion and spherical aberrations and also contribute to greater overall sharpness and accurate rendering.
• A Super Multi-Layer Coating has been applied to lens elements in order to minimize lens flare and ghosting and contribute to producing contrast-rich and color-neutral imagery, even in backlit conditions.
• Ideal for close-up shooting, this lens offers a 1:2.8 maximum magnification along with a minimum focusing distance of 8.7" to suit working with nearby subjects.
• Integrated HSM (Hyper Sonic Motor), along with a rear focus system, realizes quick and quiet autofocus, which is further complemented by an optimized AF algorithm to produce smoother focusing performance. The HSM also permits full-time manual focus control simply by rotating the focus ring at any time.
• Rounded seven-blade diaphragm contributes to a smooth and pleasing bokeh quality.
• Constructed using a Thermally Stable Composite (TSC) material for greater precision and use in wide temperature variations. Additionally, a brass bayonet affords improved mounting accuracy and rigidity.
• This lens is compatible with the optional Sigma USB Dock for fine-tuning different lens characteristics and updating its firmware. 

Key Features

• A-Mount Lens/APS-C Format
• 25.5-105mm (35mm Equivalent)
• Aperture Range: f/2.8 to f/22
• Two FLD Elements, One SLD Element
• Three Aspherical Elements
• Super Multi-Layer Coating
• Hyper Sonic Motor AF System
• 1:2.8 Magnification, 8.7" Minimum Focus
• Rounded 7-Blade Diaphragm