The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax DA 55-300mm F4.0-5.8 ED WR and the Canon 75-300mm f4.0-5.6 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 75-300mm f4.0-5.6 III is the longer of the two lenses at 122mm. The Pentax DA 55-300mm F4.0-5.8 ED WR with a length of 112mm, is 10mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 71mm.
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 DA 55-300mm F4.0-5.8 ED WR weighs 466g, which means it is 14g (2%) lighter than the Canon 75-300mm f4.0-5.6 III which has a weight of 480g.
Filter Threads
Both the Pentax DA 55-300mm F4.0-5.8 ED WR and the Canon 75-300mm f4.0-5.6 III have the same Filter thread size of 58mm.
Below are links to the 58mm filters that we recommend you to consider for these lenses:
Lens Mounts
The Pentax DA 55-300mm F4.0-5.8 ED WR has the Pentax KAF2 lens mount whereas the Canon 75-300mm f4.0-5.6 III has the Canon EF lens mount. Some of the latest released cameras that are compatible with these mounts are , and for the Pentax KAF2 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 DA 55-300mm F4.0-5.8 ED WR has a focal range of 55-300mm and
5.5X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
82.5-450mm when used on a APS-C / DX format camera.
On the other hand, the Canon 75-300mm f4.0-5.6 III has a focal range of 75-300mm and 4.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 120 - 480mm.
