The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 70-200mm f2.8 LD and the Pentax DA 60-250mm F4.0 ED 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 70-200mm f2.8 LD is the longer of the two lenses at 194mm. The Pentax DA 60-250mm F4.0 ED with a length of 168mm, is 26mm shorter. Besides being longer, the Tamron 70-200mm f2.8 LD also has a larger diameter of 90mm compared to the Pentax DA 60-250mm F4.0 ED's 82mm 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 DA 60-250mm F4.0 ED weighs 1040g, 21% (290g) lighter than the Tamron 70-200mm f2.8 LD's weight of 1330g.
Filter Threads
The Tamron 70-200mm f2.8 LD has a filter size of 77mm whereas the Pentax DA 60-250mm F4.0 ED has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 77mm filters that we recommend you to consider for the Tamron 70-200mm f2.8 LD:
And these are the 67mm filters that we recommend for the Pentax DA 60-250mm F4.0 ED:
Lens Mounts
The Tamron 70-200mm f2.8 LD has the Pentax KAF lens mount whereas the Pentax DA 60-250mm F4.0 ED has the Pentax KAF2 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 KAF Mount and , and for the Pentax KAF2 Mount.
Tamron 70-200mm f2.8 LD is also available in the Canon EF , Nikon F (FX) and Sony Alpha mounts.
Focal Range
Tamron 70-200mm f2.8 LD has a focal range of 70-200mm and
2.9X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
105 - 300mm.
On the other hand, the Pentax DA 60-250mm F4.0 ED has a focal range of 60-250mm and 4.2X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 90-375mm when used on a APS-C / DX format camera.
