The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 24-105mm F4L IS II and the Canon 800mm f5.6L 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 800mm f5.6L IS USM is the longer of the two lenses at 461mm. The Canon 24-105mm F4L IS II with a length of 118mm, is 343mm shorter. Besides being longer, the Canon 800mm f5.6L IS USM also has a larger diameter of 163mm compared to the Canon 24-105mm F4L IS II's 84mm 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 24-105mm F4L IS II weighs 795g, which means it is 3705g (82%) lighter than the Canon 800mm f5.6L IS USM which has a weight of 4500g.
Filter Threads
The Canon 24-105mm F4L IS II has a filter size of 77mm whereas the Canon 800mm f5.6L IS USM has a 52mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 77mm filters that we recommend you to consider for the Canon 24-105mm F4L IS II:
And these are the 52mm filters that we recommend for the Canon 800mm f5.6L IS USM:
Lens Mounts
Both the Canon 24-105mm F4L IS II and the Canon 800mm f5.6L IS USM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Focal Range
Canon 24-105mm F4L IS II has a focal range of 24-105mm and
4.4X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
38.4 - 168mm.
On the other hand, the Canon 800mm f5.6L IS USM is a prime lens with fixed focal lenght of 800mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 1280mm.