The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 85mm F1.4 EX DG HSM and the Pentax D-FA 100mm F2.8 Macro for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Sigma 85mm F1.4 EX DG HSM is the longer of the two lenses at 88mm. The Pentax D-FA 100mm F2.8 Macro with a length of 81mm, is 7mm shorter. Besides being longer, the Sigma 85mm F1.4 EX DG HSM also has a larger diameter of 86mm compared to the Pentax D-FA 100mm F2.8 Macro's 68mm diameter.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Pentax D-FA 100mm F2.8 Macro weighs 345g, 52% (380g) lighter than the Sigma 85mm F1.4 EX DG HSM's weight of 725g.
Filter Threads
The Sigma 85mm F1.4 EX DG HSM has a filter size of 77mm whereas the Pentax D-FA 100mm F2.8 Macro has a 49mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 77mm filters that we recommend you to consider for the Sigma 85mm F1.4 EX DG HSM:
And these are the 49mm filters that we recommend for the Pentax D-FA 100mm F2.8 Macro:
Lens Mounts
The Sigma 85mm F1.4 EX DG HSM has the Pentax KAF3 lens mount whereas the Pentax D-FA 100mm F2.8 Macro has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Sigma 85mm F1.4 EX DG HSM is also available in the Canon EF , Nikon F (FX), Sony Alpha and Sigma SA mounts.
Focal Range
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 a 35mm (FF) equivalent of
127.5mm.
On the other hand, the Pentax D-FA 100mm F2.8 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 a 35mm (FF) equivalent of 150mm.
