The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 85mm F1.8 VC and the Rokinon 85mm F1.4 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. Tamron 85mm F1.8 VC is the longer of the two lenses at 91mm. The Rokinon 85mm F1.4 with a length of 75mm, is 16mm shorter. Besides being longer, the Tamron 85mm F1.8 VC also has a larger diameter of 85mm compared to the Rokinon 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. Rokinon 85mm F1.4 weighs 539g, 23% (161g) lighter than the Tamron 85mm F1.8 VC's weight of 700g.
Below you can find the dimension and weight table of the Telephoto Prime Lenses in Sony Alpha Mount for size comparison purposes.
Telephoto Prime Lenses in Sony Alpha Mount for Size Comparison
Lens Mounts
Both the Tamron 85mm F1.8 VC and the Rokinon 85mm F1.4 has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A99 II, Sony A68 and Sony A77 II.
Tamron 85mm F1.8 VC is also available in Canon EF and Nikon F (FX) mounts.
Rokinon 85mm F1.4 is also available in Canon EF , Four Thirds, Pentax KAF, Samsung NX and Nikon F (FX) mounts.
Focal Range
Both lenses have the same focal range of 85mm but while Tamron 85mm F1.8 VC has the fastest aperture of F1.8, the Rokinon 85mm F1.4's widest aperture value is F1.4.