The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 20mm F1.8 and the Canon 35mm f2 IS 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. Samyang 20mm F1.8 is the longer of the two lenses at 88mm. The Canon 35mm f2 IS USM with a length of 63mm, is 25mm shorter. Besides being longer, the Samyang 20mm F1.8 also has a larger diameter of 83mm compared to the Canon 35mm f2 IS USM's 78mm 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 35mm f2 IS USM weighs 335g, 32% (162g) lighter than the Samyang 20mm F1.8's weight of 497g.
Filter Threads
The Samyang 20mm F1.8 has a filter size of 77mm 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 77mm filters that we recommend you to consider for the Samyang 20mm F1.8:
And these are the 67mm filters that we recommend for the Canon 35mm f2 IS USM:
Lens Mounts
Both the Samyang 20mm F1.8 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 1D X III, Canon 6D MII and Canon 5D MIV.
Samyang 20mm F1.8 is also available in Canon EF-M , Fujifilm X, Micro Four Thirds, Nikon F (FX), Pentax KAF, Samsung NX, Sony Alpha and Sony E mounts.
Focal Range
Samyang 20mm F1.8 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.
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.