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 Sigma 85mm F1.4 EX DG HSM 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 Sigma 85mm F1.4 EX DG HSM with a length of 88mm, is 3mm shorter. On the other hand, the Sigma 85mm F1.4 EX DG HSM has a larger diameter of 86mm compared to the Tamron 85mm F1.8 VC's 85mm 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. Tamron 85mm F1.8 VC weighs 700g, which means it is 25g (3%) lighter than the Sigma 85mm F1.4 EX DG HSM which has a weight of 725g.
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
Both the Tamron 85mm F1.8 VC and the Sigma 85mm F1.4 EX DG HSM 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.
Tamron 85mm F1.8 VC is also available in Sony Alpha and Nikon F (FX) mounts.
Sigma 85mm F1.4 EX DG HSM is also available in Nikon F (FX) , Pentax KAF3, Sony Alpha and Sigma SA mounts.
Both lenses have the same focal range of 85mm but while Tamron 85mm F1.8 VC has the fastest aperture of F1.8, the Sigma 85mm F1.4 EX DG HSM's widest aperture value is F1.4.