The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Venus 105mm F2 and the Canon 85mm f1.8 USM for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Venus 105mm F2 is the longer of the two lenses at 99mm. The Canon 85mm f1.8 USM with a length of 72mm is 27mm shorter. Besides being longer, the Venus 105mm F2 also has a larger diameter of 76mm compared to Canon 85mm f1.8 USM's 75mm diameter.
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. Canon 85mm f1.8 USM weighs 425g, 42% (320g) lighter than the Venus 105mm F2's weight of 745g.
Below you can find the dimension and weight table of the 'Telephoto Prime Lenses in Canon EF Mount for size comparison purposes.
Telephoto Prime Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both Venus 105mm F2 and Canon 85mm f1.8 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.
Venus 105mm F2 is also available in Sony E , Nikon F (FX), Pentax KAF2 and Sony Alpha mounts.
Focal Range
Venus 105mm F2 is a prime lens with fixed focal lenght of 105mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides an 35mm (FF) equivalent of 168mm.
Canon 85mm f1.8 USM 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 an 35mm (FF) equivalent of 136mm.