The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax 12-24mm F4.0 ED AL and the Canon 16-35mm F2.8L III 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. Canon 16-35mm F2.8L III is the longer of the two lenses at 128mm. The Pentax 12-24mm F4.0 ED AL with a length of 84mm, is 44mm shorter. Besides being longer, the Canon 16-35mm F2.8L III also has a larger diameter of 89mm compared to the Pentax 12-24mm F4.0 ED AL's 88mm 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 12-24mm F4.0 ED AL weighs 430g, which means it is 360g (45%) lighter than the Canon 16-35mm F2.8L III which has a weight of 790g.
Filter Threads
The Pentax 12-24mm F4.0 ED AL has a filter size of 77mm whereas the Canon 16-35mm F2.8L III has a 82mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 77mm filters that we recommend you to consider for the Pentax 12-24mm F4.0 ED AL:
And these are the 82mm filters that we recommend for the Canon 16-35mm F2.8L III:
Lens Mounts
The Pentax 12-24mm F4.0 ED AL has the Pentax KAF lens mount whereas the Canon 16-35mm F2.8L III has the Canon EF 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 Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K for the Canon EF Mount.
Focal Range
Pentax 12-24mm F4.0 ED AL has a focal range of 12-24mm and
2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
18-36mm when used on a APS-C / DX format camera.
On the other hand, the Canon 16-35mm F2.8L III has a focal range of 16-35mm and 2.2X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 25.6 - 56mm.
