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 Macro 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 105mm F2.8 EX DG Macro is the longer of the two lenses at 98mm. The Canon 85mm f1.8 USM with a length of 72mm, is 26mm shorter. On the other hand, the Canon 85mm f1.8 USM has a larger diameter of 75mm compared to the Sigma 105mm F2.8 EX DG Macro'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. Canon 85mm f1.8 USM weighs 425g, 7% (35g) lighter than the Sigma 105mm F2.8 EX DG Macro's weight of 460g.
Filter Threads
The Sigma 105mm F2.8 EX DG Macro has a filter size of 62mm 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 62mm filters that we recommend you to consider for the Sigma 105mm F2.8 EX DG Macro:
And these are the 58mm filters that we recommend for the Canon 85mm f1.8 USM:
Lens Mounts
Both the Sigma 105mm F2.8 EX DG Macro 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 1D X III, Canon 6D MII and Canon 5D MIV.
Sigma 105mm F2.8 EX DG Macro is also available in Nikon F (FX) , Pentax KAF, Sony Alpha, Sigma SA and Four Thirds mounts.
Focal Range
Sigma 105mm F2.8 EX DG Macro is a prime lens with fixed focal lenght of 105mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
168mm.
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.