The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 11-20mm F2.8 Di III-A and the Sigma 14-24mm F2.8 DG DN Art for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Sigma 14-24mm F2.8 DG DN Art is the longer of the two lenses at 131mm. The Tamron 11-20mm F2.8 Di III-A with a length of 86mm, is 45mm shorter. Besides being longer, the Sigma 14-24mm F2.8 DG DN Art also has a larger diameter of 85mm compared to the Tamron 11-20mm F2.8 Di III-A's 73mm diameter.
The 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. Tamron 11-20mm F2.8 Di III-A weighs 335g, which means it is 460g (57%) lighter than the Sigma 14-24mm F2.8 DG DN Art which has a weight of 795g.
Below you can find the dimension and weight table of the Wideangle Zoom Lenses in Sony E Mount for size comparison purposes.
Wideangle Zoom Lenses in Sony E Mount for Size Comparison
Lens Mounts
Both the Tamron 11-20mm F2.8 Di III-A and the Sigma 14-24mm F2.8 DG DN Art has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony A7R V, Sony FX30 and Sony A7 IV.
Tamron 11-20mm F2.8 Di III-A is also available in Fujifilm X mount.
Sigma 14-24mm F2.8 DG DN Art is also available in Leica L mount.
Focal Range
Tamron 11-20mm F2.8 Di III-A has a focal range of 11-20mm and 1.8X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 16.5 - 30mm.
Sigma 14-24mm F2.8 DG DN Art 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 a 35mm (FF) equivalent of 21 - 36mm.