The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 500mm f4.0L IS II USM and the Canon 400mm F4 DO IS II USM 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 500mm f4.0L IS II USM is the longer of the two lenses at 383mm. The Canon 400mm F4 DO IS II USM with a length of 233mm, is 150mm shorter. Besides being longer, the Canon 500mm f4.0L IS II USM also has a larger diameter of 146mm 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, 34% (1090g) lighter than the Canon 500mm f4.0L IS II USM's weight of 3190g.
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
Both the Canon 500mm f4.0L IS II USM and the Canon 400mm F4 DO IS II USM have the same Filter thread size of 52mm.
Below are links to the 52mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Canon 500mm f4.0L IS II USM and the Canon 400mm F4 DO IS II USM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Focal Range
Canon 500mm f4.0L IS II USM is a prime lens with fixed focal lenght of 500mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
800mm.
On the other hand, the 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.