The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 28-75mm F2.8 Di III 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. Tamron 28-75mm F2.8 Di III is the longer of the two lenses at 118mm. The Pentax 16-50mm F2.8 ED PLM AW with a length of 117mm, is 1mm shorter. On the other hand, the Pentax 16-50mm F2.8 ED PLM AW has a larger diameter of 84mm compared to the Tamron 28-75mm F2.8 Di III'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. Tamron 28-75mm F2.8 Di III weighs 540g, which means it is 172g (24%) lighter than the Pentax 16-50mm F2.8 ED PLM AW which has a weight of 712g.
Filter Threads
The Tamron 28-75mm F2.8 Di III has a filter size of 67mm whereas the Pentax 16-50mm F2.8 ED PLM AW has a 77mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Tamron 28-75mm F2.8 Di III:
And these are the 77mm filters that we recommend for the Pentax 16-50mm F2.8 ED PLM AW:
Lens Mounts
The Tamron 28-75mm F2.8 Di III has the Nikon Z 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 Nikon ZR, Nikon Z5 II and RED Komodo-X 6K Z for the Nikon Z Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF4 Mount.
Tamron 28-75mm F2.8 Di III is also available in the Sony E and Sony E mounts.
Focal Range
Tamron 28-75mm F2.8 Di III has a focal range of 28-75mm and
2.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
42 - 112.5mm.
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.
