The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Rokinon 85mm F1.8 and the Sigma 70mm F2.8 DG Macro for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Sigma 70mm F2.8 DG Macro is the longer of the two lenses at 106mm. The Rokinon 85mm F1.8 with a length of 81mm is 25mm shorter. Besides being longer, the Sigma 70mm F2.8 DG Macro also has a larger diameter of 71mm 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, which means it is 171g (33%) lighter than the Sigma 70mm F2.8 DG Macro which has a weight of 515g.
Both Rokinon 85mm F1.8 and Sigma 70mm F2.8 DG Macro has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony FX30, Sony ZV-E10 and Sony A6600.
Rokinon 85mm F1.8 is also available in Canon EF-M and Fujifilm X mounts.
Sigma 70mm F2.8 DG Macro is also available in Canon EF , Nikon F (FX) and Sigma SA mounts.
Rokinon 85mm F1.8 is a prime lens with fixed focal lenght of 85mm which has a 35mm equivalent focal range of 127.5mm when used on a APS-C / DX format camera. Sigma 70mm F2.8 DG Macro is a prime lens with fixed focal lenght of 70mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 105mm.