The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang MF 85mm F1.4 Mk2 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. Pentax D-FA 100mm F2.8 Macro is the longer of the two lenses at 81mm. The Samyang MF 85mm F1.4 Mk2 with a length of 75mm, is 6mm shorter. On the other hand, the Samyang MF 85mm F1.4 Mk2 has a larger diameter of 78mm 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, 37% (203g) lighter than the Samyang MF 85mm F1.4 Mk2's weight of 548g.
Filter Threads
The Samyang MF 85mm F1.4 Mk2 has a filter size of 72mm 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 72mm filters that we recommend you to consider for the Samyang MF 85mm F1.4 Mk2:
And these are the 49mm filters that we recommend for the Pentax D-FA 100mm F2.8 Macro:
Lens Mounts
The Samyang MF 85mm F1.4 Mk2 has the Sony E 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 Sony A9 III, Sony A7C Mark II and Sony A7CR for the Sony E Mount and Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Samyang MF 85mm F1.4 Mk2 is also available in Canon EF , Canon EF-M, Fujifilm X, Micro Four Thirds and Nikon F (FX) mounts.
Focal Range
Samyang MF 85mm F1.4 Mk2 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.