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 Fujifilm XF 16-80mm F4 R OIS WR 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 Fujifilm XF 16-80mm F4 R OIS WR with a length of 89mm, is 114mm shorter. Besides being longer, the Sigma 120-400mm F4.5-5.6 DG HSM also has a larger diameter of 92mm compared to the Fujifilm XF 16-80mm F4 R OIS WR's 78mm 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. Fujifilm XF 16-80mm F4 R OIS WR weighs 440g, 73% (1200g) lighter than the Sigma 120-400mm F4.5-5.6 DG HSM's weight of 1640g.
Filter Threads
The Sigma 120-400mm F4.5-5.6 DG HSM has a filter size of 77mm whereas the Fujifilm XF 16-80mm F4 R OIS WR has a 72mm 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 Sigma 120-400mm F4.5-5.6 DG HSM:
And these are the 72mm filters that we recommend for the Fujifilm XF 16-80mm F4 R OIS WR:
Lens Mounts
The Sigma 120-400mm F4.5-5.6 DG HSM has the Pentax KAF3 lens mount whereas the Fujifilm XF 16-80mm F4 R OIS WR has the Fujifilm X lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount and Fujifilm X-T30 III, Fujifilm X-E5 and Fujifilm X-M5 for the Fujifilm X Mount.
Sigma 120-400mm F4.5-5.6 DG HSM is also available in the Sony Alpha mount.
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 Fujifilm XF 16-80mm F4 R OIS WR has a focal range of 16-80mm and 5.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 24-120mm when used on a APS-C / DX format camera.
