The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 18-200mm F3.5-6.3 DC OS HSM and the Nikon 24-120mm f3.5-5.6G ED-IF 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. Sigma 18-200mm F3.5-6.3 DC OS HSM is the longer of the two lenses at 98mm. The Nikon 24-120mm f3.5-5.6G ED-IF VR with a length of 94mm, is 4mm shorter. Besides being longer, the Sigma 18-200mm F3.5-6.3 DC OS HSM also has a larger diameter of 79mm compared to the Nikon 24-120mm f3.5-5.6G ED-IF VR's 77mm 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. Nikon 24-120mm f3.5-5.6G ED-IF VR weighs 575g, 4% (25g) lighter than the Sigma 18-200mm F3.5-6.3 DC OS HSM's weight of 600g.
Filter Threads
Both the Sigma 18-200mm F3.5-6.3 DC OS HSM and the Nikon 24-120mm f3.5-5.6G ED-IF VR have the same Filter thread size of 72mm.
Below are links to the 72mm filters that we recommend you to consider for these lenses:
Lens Mounts
The Sigma 18-200mm F3.5-6.3 DC OS HSM has the Sigma SA lens mount whereas the Nikon 24-120mm f3.5-5.6G ED-IF VR has the Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with these mounts are Sigma SD1 Merrill, Sigma SD1 and for the Sigma SA Mount and Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount.
Sigma 18-200mm F3.5-6.3 DC OS HSM is also available in the Canon EF and Nikon F (DX) mounts.
Focal Range
Sigma 18-200mm F3.5-6.3 DC OS HSM has a focal range of 18-200mm and
11.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
27-300mm when used on a APS-C / DX format camera.
On the other hand, the Nikon 24-120mm f3.5-5.6G ED-IF 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.
