The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 24-70mm F2.8 DG OS HSM and the Nikon 24-120mm f4G ED VR 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 DG OS HSM is the longer of the two lenses at 108mm. The Nikon 24-120mm f4G ED VR with a length of 104mm is 4mm shorter. Besides being longer, the Sigma 24-70mm F2.8 DG OS HSM also has a larger diameter of 88mm compared to Nikon 24-120mm f4G ED VR's 84mm 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. Nikon 24-120mm f4G ED VR weighs 710g, 30% (310g) lighter than the Sigma 24-70mm F2.8 DG OS HSM's weight of 1020g.
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 Sigma 24-70mm F2.8 DG OS HSM and Nikon 24-120mm f4G ED VR 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.
Sigma 24-70mm F2.8 DG OS HSM is also available in Sigma SA and Canon EF mounts.
Focal Range
Sigma 24-70mm F2.8 DG OS HSM 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.
Nikon 24-120mm f4G ED VR has a focal range of 24-120mm and 5.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 36 - 180mm.