The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 105mm F2.8 EX DG OS HSM and the Canon 24-85mm f3.5-4.5 USM 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 105mm F2.8 EX DG OS HSM is the longer of the two lenses at 127mm. The Canon 24-85mm f3.5-4.5 USM with a length of 70mm, is 57mm shorter. Besides being longer, the Sigma 105mm F2.8 EX DG OS HSM also has a larger diameter of 78mm compared to the Canon 24-85mm f3.5-4.5 USM's 73mm 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. Canon 24-85mm f3.5-4.5 USM weighs 380g, 47% (346g) lighter than the Sigma 105mm F2.8 EX DG OS HSM's weight of 726g.
Filter Threads
The Sigma 105mm F2.8 EX DG OS HSM has a filter size of 62mm whereas the Canon 24-85mm f3.5-4.5 USM has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 62mm filters that we recommend you to consider for the Sigma 105mm F2.8 EX DG OS HSM:
And these are the 67mm filters that we recommend for the Canon 24-85mm f3.5-4.5 USM:
Lens Mounts
The Sigma 105mm F2.8 EX DG OS HSM has the Sigma SA lens mount whereas the Canon 24-85mm f3.5-4.5 USM has the Canon EF lens mount. Some of the latest released cameras that are compatible with these mounts are Sigma Quattro, Sigma Quattro H and Sigma SD1 Merrill for the Sigma SA Mount and Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K for the Canon EF Mount.
Sigma 105mm F2.8 EX DG OS HSM is also available in the Canon EF and Nikon F (FX) mounts.
Focal Range
Sigma 105mm F2.8 EX DG OS HSM is a prime lens with fixed focal lenght of 105mm.
On the other hand, the Canon 24-85mm f3.5-4.5 USM has a focal range of 24-85mm and 3.5X 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 - 136mm.
