The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon EF 70-200 F2.8L IS III USM and the Canon 300mm f4.0L 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 300mm f4.0L IS USM is the longer of the two lenses at 221mm. The Canon EF 70-200 F2.8L IS III USM with a length of 199mm, is 22mm shorter. Besides being longer, the Canon 300mm f4.0L IS USM also has a larger diameter of 90mm compared to the Canon EF 70-200 F2.8L IS III USM's 89mm 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 300mm f4.0L IS USM weighs 1190g, 17% (250g) lighter than the Canon EF 70-200 F2.8L IS III USM's weight of 1440g.
Filter Threads
Both the Canon EF 70-200 F2.8L IS III USM and the Canon 300mm f4.0L IS USM have the same Filter thread size of 77mm.
Below are links to the 77mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Canon EF 70-200 F2.8L IS III USM and the Canon 300mm f4.0L IS USM 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.
Focal Range
Canon EF 70-200 F2.8L IS III USM has a focal range of 70-200mm and
2.9X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
112 - 320mm.
On the other hand, the Canon 300mm f4.0L IS USM is a prime lens with fixed focal lenght of 300mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 480mm.
