The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon RF 1200mm F8L and the Sigma 300-800mm F5.6 EX DG HSM 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. Sigma 300-800mm F5.6 EX DG HSM is the longer of the two lenses at 544mm. The Canon RF 1200mm F8L with a length of 537mm, is 7mm shorter. On the other hand, the Canon RF 1200mm F8L has a larger diameter of 168mm compared to the Sigma 300-800mm F5.6 EX DG HSM's 157mm 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 RF 1200mm F8L weighs 3340g, which means it is 2540g (43%) lighter than the Sigma 300-800mm F5.6 EX DG HSM which has a weight of 5880g.
Filter Threads
The Canon RF 1200mm F8L has a filter size of 52mm whereas the Sigma 300-800mm F5.6 EX DG HSM has a 46mm 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 RF 1200mm F8L:
And these are the 46mm filters that we recommend for the Sigma 300-800mm F5.6 EX DG HSM:
Lens Mounts
The Canon RF 1200mm F8L has the Canon RF lens mount whereas the Sigma 300-800mm F5.6 EX DG HSM has the Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with these mounts are Canon R6 V, Canon R6 III and Canon C50 for the Canon RF Mount and Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount.
Sigma 300-800mm F5.6 EX DG HSM is also available in Sigma SA and Canon EF mounts.
Focal Range
Canon RF 1200mm F8L is a prime lens with fixed focal lenght of 1200mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
1920mm.
On the other hand, the Sigma 300-800mm F5.6 EX DG HSM has a focal range of 300-800mm and 2.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 450 - 1200mm.
