The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax D FA 24-70mm F2.8 ED SDM WR and the Pentax 16-85mm F3.5-5.6 ED DC WR 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 24-70mm F2.8 ED SDM WR is the longer of the two lenses at 110mm. The Pentax 16-85mm F3.5-5.6 ED DC WR with a length of 94mm, is 16mm shorter. Besides being longer, the Pentax D FA 24-70mm F2.8 ED SDM WR also has a larger diameter of 89mm compared to the Pentax 16-85mm F3.5-5.6 ED DC WR's 78mm diameter.
ss
Below you can find a scaled side-by-side image of Pentax D FA 24-70mm F2.8 ED SDM WR and Pentax 16-85mm F3.5-5.6 ED DC WR to get a better idea of how their sizes compare in real life.
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 16-85mm F3.5-5.6 ED DC WR weighs 488g, 37% (299g) lighter than the Pentax D FA 24-70mm F2.8 ED SDM WR's weight of 787g.
Below you can find the dimension and weight table of the Standard Zoom Lenses in Pentax KAF3 Mount for size comparison purposes.
Standard Lenses in Pentax KAF3 Mount for Size Comparison
Lens Mounts
Both the Pentax D FA 24-70mm F2.8 ED SDM WR and the Pentax 16-85mm F3.5-5.6 ED DC WR has the same Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with the Pentax KAF3 lenses are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III.
Focal Range
Pentax D FA 24-70mm F2.8 ED SDM WR has a focal range of 24-70mm and
2.9X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
36 - 105mm.
On the other hand, the Pentax 16-85mm F3.5-5.6 ED DC WR has a focal range of 16-85mm and 5.3X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 24-127.5mm when used on a APS-C / DX format camera.