The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 18-300mm F3.5-6.3 Di and the Pentax 18-270mm F3.5-6.3 ED SDM 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 18-300mm F3.5-6.3 Di is the longer of the two lenses at 126mm. The Pentax 18-270mm F3.5-6.3 ED SDM with a length of 89mm, is 37mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 76mm.
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 18-270mm F3.5-6.3 ED SDM weighs 453g, 26% (167g) lighter than the Tamron 18-300mm F3.5-6.3 Di's weight of 620g.
Filter Threads
The Tamron 18-300mm F3.5-6.3 Di has a filter size of 67mm whereas the Pentax 18-270mm F3.5-6.3 ED SDM 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 67mm filters that we recommend you to consider for the Tamron 18-300mm F3.5-6.3 Di:
And these are the 62mm filters that we recommend for the Pentax 18-270mm F3.5-6.3 ED SDM:
Lens Mounts
The Tamron 18-300mm F3.5-6.3 Di has the Sony E lens mount whereas the Pentax 18-270mm F3.5-6.3 ED SDM has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Sony ZV-E10 II, Sony A6700 and Sony FX30 for the Sony E Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Tamron 18-300mm F3.5-6.3 Di is also available in the Fujifilm X mount.
Focal Range
Tamron 18-300mm F3.5-6.3 Di has a focal range of 18-300mm and
16.7X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
27-450mm when used on a APS-C / DX format camera.
On the other hand, the Pentax 18-270mm F3.5-6.3 ED SDM has a focal range of 18-270mm and 15.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-405mm when used on a APS-C / DX format camera.
