The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 24-105mm F4L IS II 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. Canon 24-105mm F4L IS II is the longer of the two lenses at 118mm. The Sigma 17-50mm F2.8 EX DC OS HSM with a length of 92mm, is 26mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 84mm.
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% (230g) lighter than the Canon 24-105mm F4L IS II's weight of 795g.
Below you can find the dimension and weight table of the Standard Zoom Lenses in Canon EF Mount for size comparison purposes.
Standard Lenses in Canon EF Mount for Size Comparison
Filter Threads
Both the Canon 24-105mm F4L IS II and the Sigma 17-50mm F2.8 EX DC OS HSM have the same Filter thread size of 77mm.
Below are links to the 77mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Canon 24-105mm F4L IS II and the Sigma 17-50mm F2.8 EX DC OS HSM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Sigma 17-50mm F2.8 EX DC OS HSM is also available in Pentax KAF3 , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Canon 24-105mm F4L IS II has a focal range of 24-105mm and
4.4X 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 - 168mm.
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 27.2-80mm when used on a APS-C / DX format camera.