The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron SP 70-200mm 2.8 Di VC USD G2 and the Sigma 300-800mm F5.6 EX 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 300-800mm F5.6 EX DG HSM is the longer of the two lenses at 544mm. The Tamron SP 70-200mm 2.8 Di VC USD G2 with a length of 194mm is 350mm shorter. Besides being longer, the Sigma 300-800mm F5.6 EX DG HSM also has a larger diameter of 157mm compared to Tamron SP 70-200mm 2.8 Di VC USD G2's 88mm 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 SP 70-200mm 2.8 Di VC USD G2 weighs 1500g, which means it is 4380g (74%) lighter than the Sigma 300-800mm F5.6 EX DG HSM which has a weight of 5880g.
Below you can find the dimension and weight table of the 'Telephoto Zoom Lenses in Nikon F (FX) Mount for size comparison purposes.
Telephoto Zoom Lenses in Nikon F (FX) Mount for Size Comparison
Lens Mounts
Both Tamron SP 70-200mm 2.8 Di VC USD G2 and Sigma 300-800mm F5.6 EX DG HSM 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 SP 70-200mm 2.8 Di VC USD G2 is also available in Canon EF mount.
Sigma 300-800mm F5.6 EX DG HSM is also available in Sigma SA and Canon EF mounts.
Focal Range
Tamron SP 70-200mm 2.8 Di VC USD G2 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.
Sigma 300-800mm F5.6 EX DG HSM has a focal range of 300-800mm and 2.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 450 - 1200mm.