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 USM and the Canon 400mm f2.8L IS 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 USM is the longer of the two lenses at 387mm. The Canon 400mm f2.8L IS USM with a length of 349mm, is 38mm shorter. On the other hand, the Canon 400mm f2.8L IS USM has a larger diameter of 163mm compared to the Canon 500mm f4.0L IS USM's 146mm 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 500mm f4.0L IS USM weighs 3870g, which means it is 1500g (27%) lighter than the Canon 400mm f2.8L IS USM which has a weight of 5370g.
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 USM and the Canon 400mm f2.8L IS 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 USM and the Canon 400mm f2.8L IS 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 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 f2.8L IS 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.