The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 14-24mm F2.8 DG HSM and the Tokina AT-X 14-20mm F2 Pro DX 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 14-24mm F2.8 DG HSM is the longer of the two lenses at 135mm. The Tokina AT-X 14-20mm F2 Pro DX with a length of 106mm is 29mm shorter. Besides being longer, the Sigma 14-24mm F2.8 DG HSM also has a larger diameter of 96mm compared to Tokina AT-X 14-20mm F2 Pro DX's 89mm 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. Tokina AT-X 14-20mm F2 Pro DX weighs 725g, 36% (425g) lighter than the Sigma 14-24mm F2.8 DG HSM's weight of 1150g.
Lens Mounts
Both Sigma 14-24mm F2.8 DG HSM has the Nikon F (FX) lens mount whereas the Tokina AT-X 14-20mm F2 Pro DX has the Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount and Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount.
Sigma 14-24mm F2.8 DG HSM is also available in Canon EF and Sigma SA mounts.
Tokina AT-X 14-20mm F2 Pro DX is also available in Canon EF mount.
Focal Range
Sigma 14-24mm F2.8 DG HSM has a focal range of 14-24mm and 1.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 21 - 36mm.
Tokina AT-X 14-20mm F2 Pro DX has a focal range of 14-20mm and 1.4X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 21-30mm when used on a APS-C / DX format camera.