The type of photography that you are planning to use is an important decision factor. Here we have evaluated the PENTAX15-30mm F2.8 ED WR and the Nikon Z 50mm F1.8 S 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. PENTAX15-30mm F2.8 ED WR is the longer of the two lenses at 144mm. The Nikon Z 50mm F1.8 S with a length of 87mm, is 57mm shorter. Besides being longer, the PENTAX15-30mm F2.8 ED WR also has a larger diameter of 99mm compared to the Nikon Z 50mm F1.8 S's 76mm 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. Nikon Z 50mm F1.8 S weighs 415g, 60% (625g) lighter than the PENTAX15-30mm F2.8 ED WR's weight of 1040g.
Lens Mounts
The PENTAX15-30mm F2.8 ED WR has the Pentax KAF3 lens mount whereas the Nikon Z 50mm F1.8 S has the Nikon Z 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 Nikon ZR, Nikon Z5 II and RED Komodo-X 6K Z for the Nikon Z Mount.
Focal Range
PENTAX15-30mm F2.8 ED WR has a focal range of 15-30mm and
2.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
22.5 - 45mm.
On the other hand, the Nikon Z 50mm F1.8 S 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.