The type of photography that you are planning to use is an important decision factor. Here we have evaluated the PENTAX 55-300mm F4.5-6.3 ED WR and the Tamron AF 70-300mm f4-5.6 LD 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. Tamron AF 70-300mm f4-5.6 LD is the longer of the two lenses at 117mm. The PENTAX 55-300mm F4.5-6.3 ED WR with a length of 89mm, is 28mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 77mm.
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. Tamron AF 70-300mm f4-5.6 LD weighs 435g, 7% (36g) lighter than the PENTAX 55-300mm F4.5-6.3 ED WR's weight of 471g.
Filter Threads
The PENTAX 55-300mm F4.5-6.3 ED WR has a filter size of 58mm whereas the Tamron AF 70-300mm f4-5.6 LD has a 62mm 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 F4.5-6.3 ED WR:
And these are the 62mm filters that we recommend for the Tamron AF 70-300mm f4-5.6 LD:
Lens Mounts
The PENTAX 55-300mm F4.5-6.3 ED WR has the Pentax KAF3 lens mount whereas the Tamron AF 70-300mm f4-5.6 LD has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount and Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Tamron AF 70-300mm f4-5.6 LD is also available in Canon EF , Nikon F (FX) and Sony Alpha mounts.
Focal Range
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.
On the other hand, the Tamron AF 70-300mm f4-5.6 LD has a focal range of 70-300mm and 4.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 105 - 450mm.