The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Zeiss Otus 100mm F1.4 and the Canon 400mm f2.8L IS II USM for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Canon 400mm f2.8L IS II USM is the longer of the two lenses at 343mm. The Zeiss Otus 100mm F1.4 with a length of 129mm is 214mm shorter. Besides being longer, the Canon 400mm f2.8L IS II USM also has a larger diameter of 163mm compared to Zeiss Otus 100mm F1.4's 101mm diameter.
Weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Zeiss Otus 100mm F1.4 weighs 1405g, which means it is 2445g (63%) lighter than the Canon 400mm f2.8L IS II USM which has a weight of 3850g.
Below you can find the dimension and weight table of the 'Telephoto Prime Lenses in Canon EF Mount for size comparison purposes.
Telephoto Prime Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both Zeiss Otus 100mm F1.4 and Canon 400mm f2.8L 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.
Zeiss Otus 100mm F1.4 is also available in Nikon F (FX) mount.
Focal Range
Zeiss Otus 100mm F1.4 is a prime lens with fixed focal lenght of 100mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides an 35mm (FF) equivalent of 160mm.
Canon 400mm f2.8L 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 an 35mm (FF) equivalent of 640mm.