The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon EF 400mm F2.8L IS III USM and the Sigma 300-800mm F5.6 EX 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 300-800mm F5.6 EX DG HSM is the longer of the two lenses at 544mm. The Canon EF 400mm F2.8L IS III USM with a length of 343mm, is 201mm shorter. On the other hand, the Canon EF 400mm F2.8L IS III USM has a larger diameter of 163mm compared to the Sigma 300-800mm F5.6 EX DG HSM's 157mm 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. Canon EF 400mm F2.8L IS III USM weighs 2840g, which means it is 3040g (51%) lighter than the Sigma 300-800mm F5.6 EX DG HSM which has a weight of 5880g.
Filter Threads
The Canon EF 400mm F2.8L IS III USM has a filter size of 52mm whereas the Sigma 300-800mm F5.6 EX DG HSM has a 46mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 52mm filters that we recommend you to consider for the Canon EF 400mm F2.8L IS III USM:
And these are the 46mm filters that we recommend for the Sigma 300-800mm F5.6 EX DG HSM:
Lens Mounts
Both the Canon EF 400mm F2.8L IS III USM and the Sigma 300-800mm F5.6 EX DG HSM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K.
Sigma 300-800mm F5.6 EX DG HSM is also available in Sigma SA and Nikon F (FX) mounts.
Focal Range
Canon EF 400mm F2.8L IS III USM is a prime lens with fixed focal lenght of 400mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
640mm.
On the other hand, the Sigma 300-800mm F5.6 EX DG HSM has a focal range of 300-800mm and 2.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 480 - 1280mm.
