The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon RF 24-70mm F2.8L and the Sigma 4.5mm F2.8 EX DC HSM Fisheye 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 RF 24-70mm F2.8L is the longer of the two lenses at 126mm. The Sigma 4.5mm F2.8 EX DC HSM Fisheye with a length of 78mm, is 48mm shorter. Besides being longer, the Canon RF 24-70mm F2.8L also has a larger diameter of 89mm compared to the Sigma 4.5mm F2.8 EX DC HSM Fisheye's 76mm 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. Sigma 4.5mm F2.8 EX DC HSM Fisheye weighs 470g, 47% (430g) lighter than the Canon RF 24-70mm F2.8L's weight of 900g.
Lens Mounts
The Canon RF 24-70mm F2.8L has the Canon RF lens mount whereas the Sigma 4.5mm F2.8 EX DC HSM Fisheye 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 Canon T8i, Canon 90D and Canon SL3 for the Canon EF Mount.
Sigma 4.5mm F2.8 EX DC HSM Fisheye is also available in Sigma SA and Nikon F (DX) mounts.
Focal Range
Canon RF 24-70mm F2.8L has a focal range of 24-70mm 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
38.4 - 112mm.
On the other hand, the Sigma 4.5mm F2.8 EX DC HSM Fisheye is a prime lens with fixed focal lenght of 5mm which has an effective (full-frame 35mm equivalent) focal range of 8mm when used on a APS-C / DX format camera.
