The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax D FA 150-450mm F4.5-5.6 ED DC AW and the Sigma 70-200mm F2.8 EX DG OS HSM 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 D FA 150-450mm F4.5-5.6 ED DC AW is the longer of the two lenses at 242mm. The Sigma 70-200mm F2.8 EX DG OS HSM with a length of 197mm, is 45mm shorter. Besides being longer, the Pentax D FA 150-450mm F4.5-5.6 ED DC AW also has a larger diameter of 95mm compared to the Sigma 70-200mm F2.8 EX DG OS HSM's 86mm 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 70-200mm F2.8 EX DG OS HSM weighs 1430g, 28% (570g) lighter than the Pentax D FA 150-450mm F4.5-5.6 ED DC AW's weight of 2000g.
Filter Threads
The Pentax D FA 150-450mm F4.5-5.6 ED DC AW has a filter size of 86mm whereas the Sigma 70-200mm F2.8 EX DG OS HSM has a 77mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 86mm filters that we recommend you to consider for the Pentax D FA 150-450mm F4.5-5.6 ED DC AW:
And these are the 77mm filters that we recommend for the Sigma 70-200mm F2.8 EX DG OS HSM:
Lens Mounts
Both the Pentax D FA 150-450mm F4.5-5.6 ED DC AW and the Sigma 70-200mm F2.8 EX DG OS HSM has the same Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with the Pentax KAF3 lenses are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III.
Sigma 70-200mm F2.8 EX DG OS HSM is also available in Canon EF , Nikon F (FX), Sony Alpha and Sigma SA mounts.
Focal Range
Pentax D FA 150-450mm F4.5-5.6 ED DC AW has a focal range of 150-450mm and
3.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
225 - 675mm.
On the other hand, the Sigma 70-200mm F2.8 EX DG OS HSM 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.