The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma APO 180mm F2.8 EX DG OS HSM and the Canon 15-85mm f3.5-5.6 IS 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 APO 180mm F2.8 EX DG OS HSM is the longer of the two lenses at 204mm. The Canon 15-85mm f3.5-5.6 IS USM with a length of 88mm, is 116mm shorter. Besides being longer, the Sigma APO 180mm F2.8 EX DG OS HSM also has a larger diameter of 95mm compared to the Canon 15-85mm f3.5-5.6 IS USM's 82mm 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 15-85mm f3.5-5.6 IS USM weighs 575g, 64% (1065g) lighter than the Sigma APO 180mm F2.8 EX DG OS HSM's weight of 1640g.
Filter Threads
The Sigma APO 180mm F2.8 EX DG OS HSM has a filter size of 86mm whereas the Canon 15-85mm f3.5-5.6 IS USM has a 72mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 86mm filters that we recommend you to consider for the Sigma APO 180mm F2.8 EX DG OS HSM:
And these are the 72mm filters that we recommend for the Canon 15-85mm f3.5-5.6 IS USM:
Lens Mounts
The Sigma APO 180mm F2.8 EX DG OS HSM has the Canon EF lens mount whereas the Canon 15-85mm f3.5-5.6 IS USM has the Canon EF-S 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 Canon T8i, Canon 90D and Canon SL3 for the Canon EF-S Mount.
Sigma APO 180mm F2.8 EX DG OS HSM is also available in the Nikon F (FX) , Sigma SA and Sony Alpha mounts.
Focal Range
Sigma APO 180mm F2.8 EX DG OS HSM is a prime lens with fixed focal lenght of 180mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
288mm.
On the other hand, the Canon 15-85mm f3.5-5.6 IS USM has a focal range of 15-85mm and 5.7X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 24-136mm when used on a APS-C / DX format camera.
