The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 400mm F4 DO IS II USM 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. Canon 400mm F4 DO IS II USM is the longer of the two lenses at 233mm. The Sigma 120-400mm F4.5-5.6 DG OS HSM with a length of 203mm, is 30mm shorter. Besides being longer, the Canon 400mm F4 DO IS II USM also has a larger diameter of 128mm 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. Sigma 120-400mm F4.5-5.6 DG OS HSM weighs 1640g, 21% (460g) lighter than the Canon 400mm F4 DO IS II USM's weight of 2100g.
Filter Threads
The Canon 400mm F4 DO IS II USM has a filter size of 52mm whereas the Sigma 120-400mm F4.5-5.6 DG OS 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 52mm filters that we recommend you to consider for the Canon 400mm F4 DO IS II USM:
And these are the 77mm filters that we recommend for the Sigma 120-400mm F4.5-5.6 DG OS HSM:
Lens Mounts
Both the Canon 400mm F4 DO IS II USM and the Sigma 120-400mm F4.5-5.6 DG OS 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 120-400mm F4.5-5.6 DG OS HSM is also available in Sigma SA and Nikon F (FX) mounts.
Focal Range
Canon 400mm F4 DO IS II 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 120-400mm F4.5-5.6 DG OS HSM has a focal range of 120-400mm and 3.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 192 - 640mm.
