Sigma's new 20-40mm f/2.8 EX Aspherical DF lens combines a constant f/2.8 maximum aperture with ultrawide-to-wide focal lengths in a new design which is easier to handhold. The lens incorporates a "Dual Focus" mechanism, which makes the focus ring stay stationary during autofocusing. Unlike most other autofocus lenses, torque of the focusing ring during manual focus remains excellent. A helical focus system eliminates front lens rotation.
2 Aspherical lens elements
Excellent close focus capability
In the Box
Sigma Zoom Super Wide Angle 20-40mm f/2.8 (D) EX Aspherical DG DF Autofocus Lens for Sony Alpha & Minolta Maxxum Series
Front & Rear Lens Caps
1-Year Worldwide Warranty + 3-Year Extended USA Warranty