The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax D-FA 100mm F2.8 Macro WR and the Samyang 85mm F1.4 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 100mm F2.8 Macro WR is the longer of the two lenses at 81mm. The Samyang 85mm F1.4 with a length of 75mm, is 6mm shorter. On the other hand, the Samyang 85mm F1.4 has a larger diameter of 78mm compared to the Pentax D-FA 100mm F2.8 Macro WR's 65mm 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 WR weighs 340g, which means it is 199g (36%) lighter than the Samyang 85mm F1.4 which has a weight of 539g.
Filter Threads
The Pentax D-FA 100mm F2.8 Macro WR has a filter size of 49mm whereas the Samyang 85mm F1.4 has a 72mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 49mm filters that we recommend you to consider for the Pentax D-FA 100mm F2.8 Macro WR:
And these are the 72mm filters that we recommend for the Samyang 85mm F1.4:
Lens Mounts
Both the Pentax D-FA 100mm F2.8 Macro WR and the Samyang 85mm F1.4 has the same Pentax KAF lens mount. Some of the latest released cameras that are compatible with the Pentax KAF lenses are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III.
Samyang 85mm F1.4 is also available in Canon EF , Nikon F (FX), Four Thirds, Sony Alpha, Sony E and Samsung NX mounts.
Focal Range
Pentax D-FA 100mm F2.8 Macro WR 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.
On the other hand, the Samyang 85mm F1.4 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.