The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 100mm f2.8L Macro IS USM and the Rokinon 85mm F1.4 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 100mm f2.8L Macro IS USM is the longer of the two lenses at 123mm. The Rokinon 85mm F1.4 with a length of 75mm, is 48mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 78mm.
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. Rokinon 85mm F1.4 weighs 539g, 13% (86g) lighter than the Canon 100mm f2.8L Macro IS USM's weight of 625g.
Filter Threads
The Canon 100mm f2.8L Macro IS USM has a filter size of 67mm whereas the Rokinon 85mm F1.4 has a 72mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Canon 100mm f2.8L Macro IS USM:
And these are the 72mm filters that we recommend for the Rokinon 85mm F1.4:
Lens Mounts
Both the Canon 100mm f2.8L Macro IS USM and the Rokinon 85mm F1.4 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.
Rokinon 85mm F1.4 is also available in Four Thirds , Pentax KAF, Sony Alpha, Samsung NX and Nikon F (FX) mounts.
Focal Range
Canon 100mm f2.8L Macro IS 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.
On the other hand, the Rokinon 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.