The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax FA 70-210mm F4 ED SDM WR and the PENTAX 55-300mm F4.5-6.3 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 FA 70-210mm F4 ED SDM WR is the longer of the two lenses at 175mm. The PENTAX 55-300mm F4.5-6.3 ED WR with a length of 89mm, is 86mm shorter. Besides being longer, the Pentax FA 70-210mm F4 ED SDM WR also has a larger diameter of 79mm compared to the PENTAX 55-300mm F4.5-6.3 ED WR's 77mm 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 55-300mm F4.5-6.3 ED WR weighs 471g, 42% (348g) lighter than the Pentax FA 70-210mm F4 ED SDM WR's weight of 819g.
Filter Threads
The Pentax FA 70-210mm F4 ED SDM WR has a filter size of 67mm whereas the PENTAX 55-300mm F4.5-6.3 ED WR has a 58mm 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 Pentax FA 70-210mm F4 ED SDM WR:
And these are the 58mm filters that we recommend for the PENTAX 55-300mm F4.5-6.3 ED WR:
Lens Mounts
The Pentax FA 70-210mm F4 ED SDM WR has the Pentax KAF4 lens mount whereas the PENTAX 55-300mm F4.5-6.3 ED WR has the Pentax KAF3 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 KAF4 Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount.
Focal Range
Pentax FA 70-210mm F4 ED SDM WR has a focal range of 70-210mm and
3.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
105-315mm when used on a APS-C / DX format camera.
On the other hand, the PENTAX 55-300mm F4.5-6.3 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.