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 200-500mm F2.8 EX DG 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 200-500mm F2.8 EX DG is the longer of the two lenses at 726mm. The Canon RF 1200mm F8L with a length of 537mm, is 189mm shorter. Besides being longer, the Sigma 200-500mm F2.8 EX DG also has a larger diameter of 237mm compared to the Canon RF 1200mm F8L's 168mm 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 12360g (78%) lighter than the Sigma 200-500mm F2.8 EX DG which has a weight of 15700g.
Filter Threads
The Canon RF 1200mm F8L has a filter size of 52mm whereas the Sigma 200-500mm F2.8 EX DG has a 72mm 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 72mm filters that we recommend for the Sigma 200-500mm F2.8 EX DG:
Lens Mounts
The Canon RF 1200mm F8L has the Canon RF lens mount whereas the Sigma 200-500mm F2.8 EX DG has the Canon EF 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 Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K for the Canon EF Mount.
Sigma 200-500mm F2.8 EX DG is also available in Sigma SA and Nikon F (FX) 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 200-500mm F2.8 EX DG has a focal range of 200-500mm and 2.5X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 320 - 800mm.