The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax D FA 70-200mm F2.8ED 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 a crucial factor to consider when comparing two lenses. Pentax D FA 70-200mm F2.8ED is the longer of the two lenses at 203mm. The Sigma 85mm F1.4 EX DG HSM with a length of 88mm, is 115mm shorter. Besides being longer, the Pentax D FA 70-200mm F2.8ED also has a larger diameter of 92mm compared to the Sigma 85mm F1.4 EX DG HSM's 86mm 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. Sigma 85mm F1.4 EX DG HSM weighs 725g, 58% (1030g) lighter than the Pentax D FA 70-200mm F2.8ED's weight of 1755g.
Filter Threads
Both the Pentax D FA 70-200mm F2.8ED and the Sigma 85mm F1.4 EX DG HSM have the same Filter thread size of 77mm.
Below are links to the 77mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Pentax D FA 70-200mm F2.8ED and the Sigma 85mm F1.4 EX DG HSM has the same Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with the Pentax KAF3 lenses are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III.
Sigma 85mm F1.4 EX DG HSM is also available in Canon EF , Nikon F (FX), Sony Alpha and Sigma SA mounts.
Focal Range
Pentax D FA 70-200mm F2.8ED has a focal range of 70-200mm and
2.9X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
105 - 300mm.
On the other hand, the 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.
