The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony 85mm F2.8 SAM and the Sigma 105mm F2.8 EX DG Macro 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 Sony 85mm F2.8 SAM with a length of 52mm, is 46mm shorter. Besides being longer, the Sigma 105mm F2.8 EX DG Macro also has a larger diameter of 74mm compared to the Sony 85mm F2.8 SAM's 70mm 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. Sony 85mm F2.8 SAM weighs 175g, which means it is 285g (61%) lighter than the Sigma 105mm F2.8 EX DG Macro which has a weight of 460g.
Filter Threads
The Sony 85mm F2.8 SAM has a filter size of 55mm whereas the Sigma 105mm F2.8 EX DG Macro has a 62mm 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 Sony 85mm F2.8 SAM:
And these are the 62mm filters that we recommend for the Sigma 105mm F2.8 EX DG Macro:
Lens Mounts
Both the Sony 85mm F2.8 SAM and the Sigma 105mm F2.8 EX DG Macro has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A99 II, Sony A68 and Sony A77 II.
Sigma 105mm F2.8 EX DG Macro is also available in Canon EF , Nikon F (FX), Pentax KAF, Sigma SA and Four Thirds mounts.
Focal Range
Sony 85mm F2.8 SAM is a prime lens with fixed focal lenght of 85mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
127.5mm.
On the other hand, the 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 1.5x crop, it provides a 35mm (FF) equivalent of 157.5mm.