The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 20mm f2.8 USM and the Sigma 12-24mm F4.5-5.6 II DG 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 12-24mm F4.5-5.6 II DG HSM is the longer of the two lenses at 120mm. The Canon 20mm f2.8 USM with a length of 71mm, is 49mm shorter. Besides being longer, the Sigma 12-24mm F4.5-5.6 II DG HSM also has a larger diameter of 87mm compared to the Canon 20mm f2.8 USM's 78mm 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. Canon 20mm f2.8 USM weighs 405g, which means it is 265g (39%) lighter than the Sigma 12-24mm F4.5-5.6 II DG HSM which has a weight of 670g.
Lens Mounts
Both the Canon 20mm f2.8 USM and the Sigma 12-24mm F4.5-5.6 II DG HSM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K.
Sigma 12-24mm F4.5-5.6 II DG HSM is also available in Sigma SA and Nikon F (FX) mounts.
Focal Range
Canon 20mm f2.8 USM is a prime lens with fixed focal lenght of 20mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
32mm.
On the other hand, the Sigma 12-24mm F4.5-5.6 II DG HSM has a focal range of 12-24mm and 2.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 19.2 - 38.4mm.
