Sigma's fast 28mm macro for Sony A — same lens as IDs 3703/3957/4162 in A-mount.
The Sigma 28mm f/1.8 EX DG Aspherical Macro for Sony A mount is the A-mount version of Sigma's unique wide-angle macro prime described in Nikon F under IDs 3703, 3957, and 4162. The combination of f/1.8 speed, 28mm wide angle, and macro close-focus to 20cm creates dramatic wide-angle perspectives impossible with other lenses.
Optical performance is the same across all mount versions. The macro close-focus at 28mm creates unique dramatic perspectives. Sharpness is respectable from f/1.8. Benefits from Sony's SteadyShot body stabilisation — an advantage over the non-stabilised Nikon and Canon versions. DG coatings reduce sensor reflections.
Sony A mount. Filter thread is 77mm. Weight is approximately 500 grams. Build quality is solid EX professional. The 20cm close-focus creates in-your-face wide-angle macro perspectives. Benefits from Sony body SR. The A-mount system is discontinued but adapts to E-mount via LA-EA adapters.
Very affordable. Check AF and focus. Same lens as other mount versions. The Sony body SR adds stabilisation absent in other mounts. Best for creative close-focus wide-angle work. The unique wide-angle macro capability remains interesting despite the age.