The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 50mm F1.4 AS UMC and the Pentax 16-50mm F2.8 ED PLM AW 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 16-50mm F2.8 ED PLM AW is the longer of the two lenses at 117mm. The Samyang 50mm F1.4 AS UMC with a length of 75mm, is 42mm shorter. Besides being longer, the Pentax 16-50mm F2.8 ED PLM AW also has a larger diameter of 84mm compared to the Samyang 50mm F1.4 AS UMC's 82mm 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. Samyang 50mm F1.4 AS UMC weighs 535g, which means it is 177g (24%) lighter than the Pentax 16-50mm F2.8 ED PLM AW which has a weight of 712g.
Filter Threads
Both the Samyang 50mm F1.4 AS UMC and the Pentax 16-50mm F2.8 ED PLM AW 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
The Samyang 50mm F1.4 AS UMC has the Pentax KAF lens mount whereas the Pentax 16-50mm F2.8 ED PLM AW has the Pentax KAF4 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 KAF Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF4 Mount.
Samyang 50mm F1.4 AS UMC is also available in the Canon EF , Nikon F (FX), Sony Alpha and Sony E mounts.
Focal Range
Samyang 50mm F1.4 AS UMC is a prime lens with fixed focal lenght of 50mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
75mm.
On the other hand, the Pentax 16-50mm F2.8 ED PLM AW has a focal range of 16-50mm and 3.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 24-75mm when used on a APS-C / DX format camera.
