The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 50-200mm F4-5.6 DC OS HSM and the Pentax 50-200mm F4-5.6 ED for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Sigma 50-200mm F4-5.6 DC OS HSM is the longer of the two lenses at 102mm. The Pentax 50-200mm F4-5.6 ED with a length of 80mm, is 22mm shorter. Besides being longer, the Sigma 50-200mm F4-5.6 DC OS HSM also has a larger diameter of 74mm compared to the Pentax 50-200mm F4-5.6 ED's 69mm diameter.
The 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. Pentax 50-200mm F4-5.6 ED weighs 272g, 35% (148g) lighter than the Sigma 50-200mm F4-5.6 DC OS HSM's weight of 420g.
Lens Mounts
The Sigma 50-200mm F4-5.6 DC OS HSM has the Pentax KAF3 lens mount whereas the Pentax 50-200mm F4-5.6 ED has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are , and for the Pentax KAF3 Mount and Pentax KF, Pentax K-3 III and Pentax KP for the Pentax KAF Mount.
Sigma 50-200mm F4-5.6 DC OS HSM is also available in Canon EF , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Both lenses have the same focal range of 50-200mm and the fastest aperture of F4.0 - F5.6.