The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax 55-300mm F4.0-5.8 ED and the Pentax 50-200mm F4-5.6 ED 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 55-300mm F4.0-5.8 ED is the longer of the two lenses at 112mm. The Pentax 50-200mm F4-5.6 ED WR with a length of 80mm, is 32mm shorter. Besides being longer, the Pentax 55-300mm F4.0-5.8 ED also has a larger diameter of 71mm compared to the Pentax 50-200mm F4-5.6 ED WR's 69mm 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 50-200mm F4-5.6 ED WR weighs 285g, 35% (155g) lighter than the Pentax 55-300mm F4.0-5.8 ED's weight of 440g.
Filter Threads
The Pentax 55-300mm F4.0-5.8 ED has a filter size of 58mm whereas the Pentax 50-200mm F4-5.6 ED WR has a 49mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 58mm filters that we recommend you to consider for the Pentax 55-300mm F4.0-5.8 ED:
And these are the 49mm filters that we recommend for the Pentax 50-200mm F4-5.6 ED WR:
Lens Mounts
Both the Pentax 55-300mm F4.0-5.8 ED and the Pentax 50-200mm F4-5.6 ED WR has the same Pentax KAF lens mount. Some of the latest released cameras that are compatible with the Pentax KAF lenses are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III.
Focal Range
Pentax 55-300mm F4.0-5.8 ED 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 Pentax 50-200mm F4-5.6 ED WR has a focal range of 50-200mm and 4.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 75-300mm when used on a APS-C / DX format camera.