The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 17-70mm F2.8-4 DC OS HSM C and the Nikon 24-120mm f4G ED VR for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Nikon 24-120mm f4G ED VR is the longer of the two lenses at 104mm. The Sigma 17-70mm F2.8-4 DC OS HSM C with a length of 82mm, is 22mm shorter. Besides being longer, the Nikon 24-120mm f4G ED VR also has a larger diameter of 84mm compared to the Sigma 17-70mm F2.8-4 DC OS HSM C's 79mm diameter.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Sigma 17-70mm F2.8-4 DC OS HSM C weighs 465g, which means it is 245g (34%) lighter than the Nikon 24-120mm f4G ED VR which has a weight of 710g.
Filter Threads
The Sigma 17-70mm F2.8-4 DC OS HSM C has a filter size of 72mm whereas the Nikon 24-120mm f4G ED VR has a 77mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 72mm filters that we recommend you to consider for the Sigma 17-70mm F2.8-4 DC OS HSM C:
And these are the 77mm filters that we recommend for the Nikon 24-120mm f4G ED VR:
Lens Mounts
The Sigma 17-70mm F2.8-4 DC OS HSM C has the Nikon F (DX) lens mount whereas the Nikon 24-120mm f4G ED VR has the Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount and Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount.
Sigma 17-70mm F2.8-4 DC OS HSM C is also available in Canon EF , Pentax KAF3, Sony Alpha and Sigma SA mounts.
Focal Range
Sigma 17-70mm F2.8-4 DC OS HSM C has a focal range of 17-70mm and
4.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
25.5-105mm when used on a APS-C / DX format camera.
On the other hand, the 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 a 35mm (FF) equivalent of 36 - 180mm.