The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron AF 70-300mm f4-5.6 LD and the Sigma 70-200mm F2.8 EX DG HSM II 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 70-200mm F2.8 EX DG HSM II is the longer of the two lenses at 184mm. The Tamron AF 70-300mm f4-5.6 LD with a length of 117mm is 67mm shorter. Besides being longer, the Sigma 70-200mm F2.8 EX DG HSM II also has a larger diameter of 87mm compared to Tamron AF 70-300mm f4-5.6 LD's 77mm 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. Tamron AF 70-300mm f4-5.6 LD weighs 435g, which means it is 955g (68%) lighter than the Sigma 70-200mm F2.8 EX DG HSM II which has a weight of 1390g.
Below you can find the dimension and weight table of the 'Telephoto Zoom Lenses in Sony Alpha Mount for size comparison purposes.
Telephoto Zoom Lenses in Sony Alpha Mount for Size Comparison
Lens Mounts
Both Tamron AF 70-300mm f4-5.6 LD and Sigma 70-200mm F2.8 EX DG HSM II 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.
Tamron AF 70-300mm f4-5.6 LD is also available in Canon EF , Nikon F (FX) and Pentax KAF mounts.
Sigma 70-200mm F2.8 EX DG HSM II is also available in Canon EF , Four Thirds, Pentax KAF3, Sigma SA and Nikon F (FX) mounts.
Focal Range
Tamron AF 70-300mm f4-5.6 LD has a focal range of 70-300mm and 4.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 105 - 450mm.
Sigma 70-200mm F2.8 EX DG HSM II has a focal range of 70-200mm and 2.9X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 105 - 300mm.