The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax D FA 24-70mm F2.8 ED SDM WR and the Sigma 24-70mm F2.8 EX DG for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Sigma 24-70mm F2.8 EX DG is the longer of the two lenses at 116mm. The Pentax D FA 24-70mm F2.8 ED SDM WR with a length of 110mm is 6mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 89mm.
Weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Sigma 24-70mm F2.8 EX DG weighs 715g, 9% (72g) lighter than the Pentax D FA 24-70mm F2.8 ED SDM WR's weight of 787g.
Lens Mounts
Both Pentax D FA 24-70mm F2.8 ED SDM WR has the Pentax KAF3 lens mount whereas the Sigma 24-70mm F2.8 EX DG has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax KF, Pentax K-3 III and Pentax K-1 II for the Pentax KAF3 Mount and Pentax KF, Pentax K-3 III and Pentax K-1 II for the Pentax KAF Mount.
Sigma 24-70mm F2.8 EX DG is also available in Canon EF , Sony Alpha, Sigma SA and Nikon F (FX) mounts.
Focal Range
Both lenses have the same focal range of 24-70mm and the fastest aperture of F2.8.