The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 8mm F3.5 EX DG Fisheye and the Canon 17-40mm f4.0L 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 17-40mm f4.0L USM is the longer of the two lenses at 97mm. The Sigma 8mm F3.5 EX DG Fisheye with a length of 69mm, is 28mm shorter. Besides being longer, the Canon 17-40mm f4.0L USM also has a larger diameter of 84mm compared to the Sigma 8mm F3.5 EX DG Fisheye's 74mm 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 8mm F3.5 EX DG Fisheye weighs 400g, which means it is 100g (19%) lighter than the Canon 17-40mm f4.0L USM which has a weight of 500g.
Lens Mounts
Both the Sigma 8mm F3.5 EX DG Fisheye and the Canon 17-40mm f4.0L 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.
Sigma 8mm F3.5 EX DG Fisheye is also available in the Nikon F (FX) and Sigma SA mounts.
Focal Range
Sigma 8mm F3.5 EX DG Fisheye is a prime lens with fixed focal lenght of 8mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
12.8mm.
On the other hand, the Canon 17-40mm f4.0L USM has a focal range of 17-40mm and 2.4X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 27.2 - 64mm.
