The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 100-400mm F5-6.3 DG OS HSM 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. Sigma 100-400mm F5-6.3 DG OS HSM is the longer of the two lenses at 182mm. The Pentax DA 60-250mm F4.0 ED with a length of 168mm, is 14mm shorter. Besides being longer, the Sigma 100-400mm F5-6.3 DG OS HSM also has a larger diameter of 86mm 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, 10% (120g) lighter than the Sigma 100-400mm F5-6.3 DG OS HSM's weight of 1160g.
Filter Threads
Both the Sigma 100-400mm F5-6.3 DG OS HSM and the Pentax DA 60-250mm F4.0 ED have the same Filter thread size of 67mm.
Below are links to the 67mm filters that we recommend you to consider for these lenses:
Lens Mounts
The Sigma 100-400mm F5-6.3 DG OS HSM has the Nikon F (FX) 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 Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount and , and for the Pentax KAF2 Mount.
Sigma 100-400mm F5-6.3 DG OS HSM is also available in the Sigma SA and Canon EF mounts.
Focal Range
Sigma 100-400mm F5-6.3 DG OS HSM has a focal range of 100-400mm and
4.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
150 - 600mm.
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.
