The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax 16-50mm F2.8 ED PLM AW and the Pentax 40mm F2.8 XS Lens 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 Pentax 40mm F2.8 XS Lens with a length of 9mm, is 108mm shorter. Besides being longer, the Pentax 16-50mm F2.8 ED PLM AW also has a larger diameter of 84mm compared to the Pentax 40mm F2.8 XS Lens's 63mm 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 40mm F2.8 XS Lens weighs 45g, 93% (667g) lighter than the Pentax 16-50mm F2.8 ED PLM AW's weight of 712g.
Lens Mounts
The Pentax 16-50mm F2.8 ED PLM AW has the Pentax KAF4 lens mount whereas the Pentax 40mm F2.8 XS Lens has the Pentax KAF 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 KAF4 Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Focal Range
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.
On the other hand, the Pentax 40mm F2.8 XS Lens is a prime lens with fixed focal lenght of 40mm which has an effective (full-frame 35mm equivalent) focal range of 60mm when used on a APS-C / DX format camera.
