The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 8-16mm F4.5-5.6 DC HSM and the Canon 15mm f2.8 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. Sigma 8-16mm F4.5-5.6 DC HSM is the longer of the two lenses at 106mm. The Canon 15mm f2.8 Fisheye with a length of 62mm, is 44mm shorter. Besides being longer, the Sigma 8-16mm F4.5-5.6 DC HSM also has a larger diameter of 75mm compared to the Canon 15mm f2.8 Fisheye's 73mm 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 15mm f2.8 Fisheye weighs 330g, 40% (225g) lighter than the Sigma 8-16mm F4.5-5.6 DC HSM's weight of 555g.
Lens Mounts
Both the Sigma 8-16mm F4.5-5.6 DC HSM and the Canon 15mm f2.8 Fisheye has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon T8i, Canon 90D and Canon SL3.
Sigma 8-16mm F4.5-5.6 DC HSM is also available in the Pentax KAF3 , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Sigma 8-16mm F4.5-5.6 DC HSM has a focal range of 8-16mm and
2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
12.8-25.6mm when used on a APS-C / DX format camera.
On the other hand, the Canon 15mm f2.8 Fisheye is a prime lens with fixed focal lenght of 15mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 24mm.
