The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Fujifilm XF 100-400mm F4.5-5.6 and the Sigma 120-400mm F4.5-5.6 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. Fujifilm XF 100-400mm F4.5-5.6 is the longer of the two lenses at 211mm. The Sigma 120-400mm F4.5-5.6 DG OS HSM with a length of 203mm, is 8mm shorter. Besides being longer, the Fujifilm XF 100-400mm F4.5-5.6 also has a larger diameter of 95mm compared to the Sigma 120-400mm F4.5-5.6 DG OS HSM's 92mm 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 100-400mm F4.5-5.6 weighs 1375g, which means it is 265g (16%) lighter than the Sigma 120-400mm F4.5-5.6 DG OS HSM which has a weight of 1640g.
Filter Threads
Both the Fujifilm XF 100-400mm F4.5-5.6 and the Sigma 120-400mm F4.5-5.6 DG OS HSM 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
The Fujifilm XF 100-400mm F4.5-5.6 has the Fujifilm X lens mount whereas the Sigma 120-400mm F4.5-5.6 DG OS HSM has the Sigma SA lens mount. Some of the latest released cameras that are compatible with these mounts are Fujifilm X-T30 III, Fujifilm X-E5 and Fujifilm X-M5 for the Fujifilm X Mount and Sigma Quattro, Sigma Quattro H and Sigma SD1 Merrill for the Sigma SA Mount.
Sigma 120-400mm F4.5-5.6 DG OS HSM is also available in Canon EF and Nikon F (FX) mounts.
Focal Range
Fujifilm XF 100-400mm F4.5-5.6 has a focal range of 100-400mm and
4.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
150-600mm when used on a APS-C / DX format camera.
On the other hand, the Sigma 120-400mm F4.5-5.6 DG OS HSM has a focal range of 120-400mm and 3.3X zoom ratio .
