The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Venus Laowa 100mm F2.8 2X Ultra Macro APO and the Rokinon 85mm F1.8 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 Laowa 100mm F2.8 2X Ultra Macro APO is the longer of the two lenses at 125mm. The Rokinon 85mm F1.8 with a length of 81mm is 44mm shorter. Besides being longer, the Venus Laowa 100mm F2.8 2X Ultra Macro APO also has a larger diameter of 72mm compared to Rokinon 85mm F1.8's 68mm 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. Rokinon 85mm F1.8 weighs 344g, 46% (294g) lighter than the Venus Laowa 100mm F2.8 2X Ultra Macro APO's weight of 638g.
Lens Mounts
Both Venus Laowa 100mm F2.8 2X Ultra Macro APO and Rokinon 85mm F1.8 has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony A7R V, Sony FX30 and Sony A7 IV.
Venus Laowa 100mm F2.8 2X Ultra Macro APO is also available in Canon EF , Nikon F (FX) and Pentax KAF2 mounts.
Rokinon 85mm F1.8 is also available in Canon EF-M and Fujifilm X mounts.
Focal Range
Venus Laowa 100mm F2.8 2X Ultra Macro APO is a prime lens with fixed focal lenght of 100mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 150mm.
Rokinon 85mm F1.8 is a prime lens with fixed focal lenght of 85mm which has a 35mm equivalent focal range of 150mm when used on a APS-C / DX format camera.