The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon TS-E 17mm f4L and the Sigma 20mm F1.8 EX DG RF 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 TS-E 17mm f4L is the longer of the two lenses at 107mm. The Sigma 20mm F1.8 EX DG RF with a length of 90mm, is 17mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 89mm.
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 20mm F1.8 EX DG RF weighs 520g, 36% (300g) lighter than the Canon TS-E 17mm f4L's weight of 820g.
Below you can find the dimension and weight table of the Perspective Control Prime Lenses in Canon EF Mount for size comparison purposes.
Ultra-Wideangle Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both the Canon TS-E 17mm f4L and the Sigma 20mm F1.8 EX DG RF has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Sigma 20mm F1.8 EX DG RF is also available in Nikon F (DX) , Pentax KAF, Sony Alpha and Sigma SA mounts.
Focal Range
Canon TS-E 17mm f4L is a prime lens with fixed focal lenght of 17mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
27.2mm.
On the other hand, the Sigma 20mm F1.8 EX DG RF is a prime lens with fixed focal lenght of 20mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 32mm.