The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tokina AT-X 14-20mm F2 Pro DX and the Sigma 12-24mm F4.5-5.6 II DG HSM for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Sigma 12-24mm F4.5-5.6 II DG HSM is the longer of the two lenses at 120mm. The Tokina AT-X 14-20mm F2 Pro DX with a length of 106mm is 14mm shorter. On the other hand, the Tokina AT-X 14-20mm F2 Pro DX has a larger diameter of 89mm compared to Sigma 12-24mm F4.5-5.6 II DG HSM's 87mm diameter.
Weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Sigma 12-24mm F4.5-5.6 II DG HSM weighs 670g, 7% (55g) lighter than the Tokina AT-X 14-20mm F2 Pro DX's weight of 725g.
Below you can find the dimension and weight table of the 'Wideangle Zoom Lenses in Canon EF Mount for size comparison purposes.
Wideangle Zoom Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both Tokina AT-X 14-20mm F2 Pro DX and 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 Canon T8i, Canon 90D and Canon SL3.
Tokina AT-X 14-20mm F2 Pro DX is also available in Nikon F (DX) mount.
Sigma 12-24mm F4.5-5.6 II DG HSM is also available in Sigma SA and Nikon F (FX) mounts.
Focal Range
Tokina AT-X 14-20mm F2 Pro DX has a focal range of 14-20mm and 1.4X zoom ratio which has a 35mm equivalent focal range of 22.4-32mm when used on a APS-C / DX format camera. 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 an 35mm (FF) equivalent of 19.2 - 38.4mm.