The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 85mm F1.4 and the Canon 100mm f2.8 Macro USM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Canon 100mm f2.8 Macro USM is the longer of the two lenses at 119mm. The Samyang 85mm F1.4 with a length of 75mm, is 44mm shorter. Besides being longer, the Canon 100mm f2.8 Macro USM also has a larger diameter of 79mm compared to the Samyang 85mm F1.4's 78mm diameter.
The weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Samyang 85mm F1.4 weighs 539g, which means it is 61g (10%) lighter than the Canon 100mm f2.8 Macro USM which has a weight of 600g.
Lens Mounts
Both the Samyang 85mm F1.4 and the Canon 100mm f2.8 Macro 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 85mm F1.4 is also available in Nikon F (FX) , Four Thirds, Pentax KAF, Sony Alpha, Sony E and Samsung NX mounts.
Focal Range
Samyang 85mm F1.4 is a prime lens with fixed focal lenght of 85mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 136mm.
Canon 100mm f2.8 Macro USM is a prime lens with fixed focal lenght of 100mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 160mm.