The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 24-70mm F2.8 EX DG HSM and the Sigma 17-50mm F2.8 EX DC 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. Sigma 24-70mm F2.8 EX DG HSM is the longer of the two lenses at 95mm. The Sigma 17-50mm F2.8 EX DC OS HSM with a length of 92mm, is 3mm shorter. Besides being longer, the Sigma 24-70mm F2.8 EX DG HSM also has a larger diameter of 89mm compared to the Sigma 17-50mm F2.8 EX DC OS HSM's 84mm 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 17-50mm F2.8 EX DC OS HSM weighs 565g, 28% (225g) lighter than the Sigma 24-70mm F2.8 EX DG HSM's weight of 790g.
Filter Threads
The Sigma 24-70mm F2.8 EX DG HSM has a filter size of 82mm whereas the Sigma 17-50mm F2.8 EX DC 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 82mm filters that we recommend you to consider for the Sigma 24-70mm F2.8 EX DG HSM:
And these are the 77mm filters that we recommend for the Sigma 17-50mm F2.8 EX DC OS HSM:
Lens Mounts
The Sigma 24-70mm F2.8 EX DG HSM has the Canon EF lens mount whereas the Sigma 17-50mm F2.8 EX DC OS HSM has the Sigma SA lens mount. Some of the latest released cameras that are compatible with these mounts are Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K for the Canon EF Mount and Sigma SD1 Merrill, Sigma SD1 and for the Sigma SA Mount.
Sigma 24-70mm F2.8 EX DG HSM is also available in the Pentax KAF3 , Sony Alpha, Sigma SA and Nikon F (FX) mounts.
Sigma 17-50mm F2.8 EX DC OS HSM is also available in Canon EF , Pentax KAF3, Sony Alpha and Nikon F (DX) mounts.
Focal Range
Sigma 24-70mm F2.8 EX DG HSM has a focal range of 24-70mm and
2.9X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
38.4 - 112mm.
On the other hand, the Sigma 17-50mm F2.8 EX DC OS HSM has a focal range of 17-50mm and 2.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 25.5-75mm when used on a APS-C / DX format camera.
