The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Venus 100mm F2.8 2X Ultra Macro and the Sigma 85mm F1.4 EX DG HSM 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 100mm F2.8 2X Ultra Macro is the longer of the two lenses at 125mm. The Sigma 85mm F1.4 EX DG HSM with a length of 88mm is 37mm shorter. On the other hand, the Sigma 85mm F1.4 EX DG HSM has a larger diameter of 86mm compared to Venus 100mm F2.8 2X Ultra Macro's 72mm 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. Venus 100mm F2.8 2X Ultra Macro weighs 638g, which means it is 87g (12%) lighter than the Sigma 85mm F1.4 EX DG HSM which has a weight of 725g.
Lens Mounts
Both Venus 100mm F2.8 2X Ultra Macro has the Pentax KAF2 lens mount whereas the Sigma 85mm F1.4 EX DG HSM has the Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax KF, Pentax K-3 III and Pentax K-1 II for the Pentax KAF2 Mount and Pentax KF, Pentax K-3 III and Pentax K-1 II for the Pentax KAF3 Mount.
Venus 100mm F2.8 2X Ultra Macro is also available in Canon EF , Nikon F (FX) and Sony E mounts.
Sigma 85mm F1.4 EX DG HSM is also available in Canon EF , Nikon F (FX), Sony Alpha and Sigma SA mounts.
Focal Range
Venus 100mm F2.8 2X Ultra Macro 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.
Sigma 85mm F1.4 EX DG HSM is a prime lens with fixed focal lenght of 85mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 127.5mm.