The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony E 70-350mm F4.5-6.3 G and the Sigma 120-400mm F4.5-5.6 DG 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 120-400mm F4.5-5.6 DG HSM is the longer of the two lenses at 203mm. The Sony E 70-350mm F4.5-6.3 G with a length of 142mm, is 61mm shorter. Besides being longer, the Sigma 120-400mm F4.5-5.6 DG HSM also has a larger diameter of 92mm compared to the Sony E 70-350mm F4.5-6.3 G'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. Sony E 70-350mm F4.5-6.3 G weighs 625g, which means it is 1015g (61%) lighter than the Sigma 120-400mm F4.5-5.6 DG HSM which has a weight of 1640g.
Filter Threads
The Sony E 70-350mm F4.5-6.3 G has a filter size of 67mm whereas the Sigma 120-400mm F4.5-5.6 DG HSM has a 77mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Sony E 70-350mm F4.5-6.3 G:
And these are the 77mm filters that we recommend for the Sigma 120-400mm F4.5-5.6 DG HSM:
Lens Mounts
The Sony E 70-350mm F4.5-6.3 G has the Sony E lens mount whereas the Sigma 120-400mm F4.5-5.6 DG HSM has the Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with these mounts are Sony ZV-E10 II, Sony A6700 and Sony FX30 for the Sony E Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount.
Sigma 120-400mm F4.5-5.6 DG HSM is also available in Sony Alpha mount.
Focal Range
Sony E 70-350mm F4.5-6.3 G has a focal range of 70-350mm and
5.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
105-525mm when used on a APS-C / DX format camera.
On the other hand, the 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.
