The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron AF 28-80mm f3.5-5.6 and the Sigma 24-70mm F2.8 EX DG 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 24-70mm F2.8 EX DG is the longer of the two lenses at 116mm. The Tamron AF 28-80mm f3.5-5.6 with a length of 70mm is 46mm shorter. Besides being longer, the Sigma 24-70mm F2.8 EX DG also has a larger diameter of 89mm compared to Tamron AF 28-80mm f3.5-5.6's 72mm 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 28-80mm f3.5-5.6 weighs 237g, which means it is 478g (66%) lighter than the Sigma 24-70mm F2.8 EX DG which has a weight of 715g.
Below you can find the dimension and weight table of the 'Standard Zoom Lenses in Nikon F (FX) Mount for size comparison purposes.
Standard Zoom Lenses in Nikon F (FX) Mount for Size Comparison
Lens Mounts
Both Tamron AF 28-80mm f3.5-5.6 and Sigma 24-70mm F2.8 EX DG has the same Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with the Nikon F (FX) lenses are Nikon D6, Nikon D780 and Nikon D3500.
Tamron AF 28-80mm f3.5-5.6 is also available in Canon EF , Sony Alpha and Pentax KAF mounts.
Sigma 24-70mm F2.8 EX DG is also available in Canon EF , Pentax KAF, Sony Alpha and Sigma SA mounts.
Focal Range
Tamron AF 28-80mm f3.5-5.6 has a focal range of 28-80mm 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 42 - 120mm.
Sigma 24-70mm F2.8 EX DG has a focal range of 24-70mm 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 36 - 105mm.