The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 300mm f2.8L IS USM and the Canon 70-300mm f4-5.6L 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 f2.8L IS USM is the longer of the two lenses at 252mm. The Canon 70-300mm f4-5.6L IS USM with a length of 143mm, is 109mm shorter. Besides being longer, the Canon 300mm f2.8L IS USM also has a larger diameter of 128mm compared to the Canon 70-300mm f4-5.6L IS 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 70-300mm f4-5.6L IS USM weighs 1050g, 58% (1500g) lighter than the Canon 300mm f2.8L IS USM's weight of 2550g.
Filter Threads
The Canon 300mm f2.8L IS USM has a filter size of 52mm whereas the Canon 70-300mm f4-5.6L IS USM has a 67mm 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 300mm f2.8L IS USM:
And these are the 67mm filters that we recommend for the Canon 70-300mm f4-5.6L IS USM:
Lens Mounts
Both the Canon 300mm f2.8L IS USM and the Canon 70-300mm f4-5.6L 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 300mm f2.8L 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.
On the other hand, the Canon 70-300mm f4-5.6L IS USM has a focal range of 70-300mm and 4.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 112 - 480mm.
