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 18-140mm f3.5-5.6G 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 18-140mm f3.5-5.6G ED VR is the longer of the two lenses at 97mm. The Sigma 17-70mm F2.8-4 DC OS HSM C with a length of 82mm, is 15mm shorter. On the other hand, the Sigma 17-70mm F2.8-4 DC OS HSM C has a larger diameter of 79mm compared to the Nikon 18-140mm f3.5-5.6G ED VR's 78mm 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 25g (5%) lighter than the Nikon 18-140mm f3.5-5.6G ED VR which has a weight of 490g.
Filter Threads
The Sigma 17-70mm F2.8-4 DC OS HSM C has a filter size of 72mm whereas the Nikon 18-140mm f3.5-5.6G ED VR has a 67mm 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 67mm filters that we recommend for the Nikon 18-140mm f3.5-5.6G ED VR:
Lens Mounts
The Sigma 17-70mm F2.8-4 DC OS HSM C has the Canon EF lens mount whereas the Nikon 18-140mm f3.5-5.6G ED VR has the Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with these mounts are Canon T8i, Canon 90D and Canon SL3 for the Canon EF Mount and Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount.
Sigma 17-70mm F2.8-4 DC OS HSM C is also available in the Pentax KAF3 , Sony Alpha, Sigma SA and Nikon F (DX) 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
27.2-112mm when used on a APS-C / DX format camera.
On the other hand, the Nikon 18-140mm f3.5-5.6G ED VR has a focal range of 18-140mm and 7.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-210mm when used on a APS-C / DX format camera.
