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 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 800mm F5.6 EX DG HSM is the longer of the two lenses at 521mm. The Canon 400mm F4 DO IS II USM with a length of 233mm, is 288mm shorter. Besides being longer, the Sigma 800mm F5.6 EX DG HSM also has a larger diameter of 157mm compared to the Canon 400mm F4 DO IS II USM's 128mm 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 400mm F4 DO IS II USM weighs 2100g, which means it is 2800g (57%) lighter than the Sigma 800mm F5.6 EX DG HSM which has a weight of 4900g.
Below you can find the dimension and weight table of the Telephoto Prime Lenses in Canon EF Mount for size comparison purposes.
Super Telephoto Lenses in Canon EF Mount for Size Comparison
Filter Threads
The Canon 400mm F4 DO IS II USM has a filter size of 52mm whereas the Sigma 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 400mm F4 DO IS II USM:
And these are the 46mm filters that we recommend for the Sigma 800mm F5.6 EX DG HSM:
Lens Mounts
Both the Canon 400mm F4 DO IS II USM and the Sigma 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 800mm F5.6 EX DG HSM is also available in Nikon F (FX) and Sigma SA 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 800mm F5.6 EX DG HSM is a prime lens with fixed focal lenght of 800mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 1280mm.
