The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 120-400mm F4.5-5.6 DG HSM and the Sigma 70-200mm F2.8 EX DG HSM II 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 120-400mm F4.5-5.6 DG HSM is the longer of the two lenses at 203mm. The Sigma 70-200mm F2.8 EX DG HSM II with a length of 184mm, is 19mm shorter. Besides being longer, the Sigma 120-400mm F4.5-5.6 DG HSM also has a larger diameter of 92mm compared to the Sigma 70-200mm F2.8 EX DG HSM II's 87mm 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 70-200mm F2.8 EX DG HSM II weighs 1390g, 15% (250g) lighter than the Sigma 120-400mm F4.5-5.6 DG HSM's weight of 1640g.
Filter Threads
Both the Sigma 120-400mm F4.5-5.6 DG HSM and the Sigma 70-200mm F2.8 EX DG HSM II have the same Filter thread size of 77mm.
Below are links to the 77mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Sigma 120-400mm F4.5-5.6 DG HSM and the Sigma 70-200mm F2.8 EX DG HSM II has the same Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with the Pentax KAF3 lenses are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III.
Sigma 120-400mm F4.5-5.6 DG HSM is also available in the Sony Alpha mount.
Sigma 70-200mm F2.8 EX DG HSM II is also available in Canon EF , Four Thirds, Sony Alpha, Sigma SA and Nikon F (FX) mounts.
Focal Range
Sigma 120-400mm F4.5-5.6 DG HSM has a focal range of 120-400mm and
3.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
180 - 600mm.
On the other hand, the Sigma 70-200mm F2.8 EX DG HSM 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.
