The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 70-200mm F2.8 GM and the Sigma 120-300mm F2.8 DG OS HSM 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 120-300mm F2.8 DG OS HSM is the longer of the two lenses at 291mm. The Sony FE 70-200mm F2.8 GM with a length of 200mm, is 91mm shorter. Besides being longer, the Sigma 120-300mm F2.8 DG OS HSM also has a larger diameter of 124mm compared to the Sony FE 70-200mm F2.8 GM's 88mm 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. Sony FE 70-200mm F2.8 GM weighs 1480g, which means it is 1470g (49%) lighter than the Sigma 120-300mm F2.8 DG OS HSM which has a weight of 2950g.
Filter Threads
The Sony FE 70-200mm F2.8 GM has a filter size of 77mm whereas the Sigma 120-300mm F2.8 DG OS HSM has a 105mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 77mm filters that we recommend you to consider for the Sony FE 70-200mm F2.8 GM:
And these are the 105mm filters that we recommend for the Sigma 120-300mm F2.8 DG OS HSM:
Lens Mounts
The Sony FE 70-200mm F2.8 GM has the Sony E lens mount whereas the Sigma 120-300mm F2.8 DG OS HSM has the Sigma SA 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 Sigma Quattro, Sigma Quattro H and Sigma SD1 Merrill for the Sigma SA Mount.
Sigma 120-300mm F2.8 DG OS HSM is also available in Canon EF and Nikon F (FX) mounts.
Focal Range
Sony FE 70-200mm F2.8 GM 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 120-300mm F2.8 DG OS HSM has a focal range of 120-300mm and 2.5X zoom ratio .
