The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 30mm F1.4 DC HSM and the Canon 35mm f2 IS USM for their suitability to various photography scenarios:
Size and Weight Comparison
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 35mm f2 IS USM weighs 335g, 22% (100g) lighter than the Sigma 30mm F1.4 DC HSM's weight of 435g.
Filter Threads
The Sigma 30mm F1.4 DC HSM has a filter size of 62mm whereas the Canon 35mm f2 IS USM has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 62mm filters that we recommend you to consider for the Sigma 30mm F1.4 DC HSM:
And these are the 67mm filters that we recommend for the Canon 35mm f2 IS USM:
Lens Mounts
Both the Sigma 30mm F1.4 DC HSM and the Canon 35mm f2 IS USM 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 30mm F1.4 DC HSM is also available in the Nikon F (DX) and Sigma SA mounts.
Focal Range
Sigma 30mm F1.4 DC HSM is a prime lens with fixed focal lenght of 30mm which has an effective (full-frame 35mm equivalent) focal range of
48mm when used on a APS-C / DX format camera.
On the other hand, the Canon 35mm f2 IS USM is a prime lens with fixed focal lenght of 35mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 56mm.