The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony 20mm F2.8 and the Sigma 8-16mm F4.5-5.6 DC HSM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Sigma 8-16mm F4.5-5.6 DC HSM is the longer of the two lenses at 106mm. The Sony 20mm F2.8 with a length of 54mm, is 52mm shorter. On the other hand, the Sony 20mm F2.8 has a larger diameter of 78mm compared to the Sigma 8-16mm F4.5-5.6 DC HSM's 75mm diameter.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Sony 20mm F2.8 weighs 285g, which means it is 270g (48%) lighter than the Sigma 8-16mm F4.5-5.6 DC HSM which has a weight of 555g.
Lens Mounts
Both the Sony 20mm F2.8 and the Sigma 8-16mm F4.5-5.6 DC HSM has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A99 II, Sony A68 and Sony A77 II.
Sigma 8-16mm F4.5-5.6 DC HSM is also available in Canon EF , Pentax KAF3, Sigma SA and Nikon F (DX) mounts.
Focal Range
Sony 20mm F2.8 is a prime lens with fixed focal lenght of 20mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
30mm.
On the other hand, the Sigma 8-16mm F4.5-5.6 DC HSM has a focal range of 8-16mm and 2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 12-24mm when used on a APS-C / DX format camera.
