The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 70-300mm F4-5.6 DG OS 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. Pentax DA 60-250mm F4.0 ED is the longer of the two lenses at 168mm. The Sigma 70-300mm F4-5.6 DG OS with a length of 126mm, is 42mm shorter. Besides being longer, the Pentax DA 60-250mm F4.0 ED also has a larger diameter of 82mm compared to the Sigma 70-300mm F4-5.6 DG OS'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. Sigma 70-300mm F4-5.6 DG OS weighs 610g, which means it is 430g (41%) lighter than the Pentax DA 60-250mm F4.0 ED which has a weight of 1040g.
Filter Threads
The Sigma 70-300mm F4-5.6 DG OS has a filter size of 58mm 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 58mm filters that we recommend you to consider for the Sigma 70-300mm F4-5.6 DG OS:
And these are the 67mm filters that we recommend for the Pentax DA 60-250mm F4.0 ED:
Lens Mounts
The Sigma 70-300mm F4-5.6 DG OS has the Pentax KAF3 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 Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount and , and for the Pentax KAF2 Mount.
Sigma 70-300mm F4-5.6 DG OS is also available in Canon EF , Nikon F (FX), Sony Alpha and Sigma SA mounts.
Focal Range
Sigma 70-300mm F4-5.6 DG OS 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.
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.