The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 70-200mm F4 G OSS II and the Sigma 17-70mm F2.8-4 DC OS HSM C 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. Sony FE 70-200mm F4 G OSS II is the longer of the two lenses at 149mm. The Sigma 17-70mm F2.8-4 DC OS HSM C with a length of 82mm, is 67mm shorter. Besides being longer, the Sony FE 70-200mm F4 G OSS II also has a larger diameter of 82mm 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, 41% (329g) lighter than the Sony FE 70-200mm F4 G OSS II's weight of 794g.
Filter Threads
Both the Sony FE 70-200mm F4 G OSS II and the Sigma 17-70mm F2.8-4 DC OS HSM C 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 Sony FE 70-200mm F4 G OSS II has the Sony E lens mount whereas the Sigma 17-70mm F2.8-4 DC OS HSM C has the Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with these mounts are Sony FX5, Sony A7R VI and Sony A7 V for the Sony E 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 Canon EF , Pentax KAF3, Sony Alpha and Sigma SA mounts.
Focal Range
Sony FE 70-200mm F4 G OSS II 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 a 35mm (FF) equivalent of
105 - 300mm.
On the other hand, the 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.