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 Canon 85mm f1.8 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 50-200mm F4-5.6 DC OS HSM is the longer of the two lenses at 102mm. The Canon 85mm f1.8 USM with a length of 72mm, is 30mm shorter. On the other hand, the Canon 85mm f1.8 USM has a larger diameter of 75mm compared to the Sigma 50-200mm F4-5.6 DC OS HSM's 74mm 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 50-200mm F4-5.6 DC OS HSM weighs 420g, which means it is 5g (1%) lighter than the Canon 85mm f1.8 USM which has a weight of 425g.
Filter Threads
The Sigma 50-200mm F4-5.6 DC OS HSM has a filter size of 55mm whereas the Canon 85mm f1.8 USM has a 58mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 55mm filters that we recommend you to consider for the Sigma 50-200mm F4-5.6 DC OS HSM:
And these are the 58mm filters that we recommend for the Canon 85mm f1.8 USM:
Lens Mounts
Both the Sigma 50-200mm F4-5.6 DC OS HSM and the Canon 85mm f1.8 USM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon T8i, Canon 90D and Canon SL3.
Sigma 50-200mm F4-5.6 DC OS HSM is also available in the Pentax KAF3 , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Sigma 50-200mm F4-5.6 DC OS HSM has a focal range of 50-200mm and
4.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
80-320mm when used on a APS-C / DX format camera.
On the other hand, the Canon 85mm f1.8 USM is a prime lens with fixed focal lenght of 85mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 136mm.
