The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 85mm F1.4 GM and the Sigma 70mm F2.8 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. Sony FE 85mm F1.4 GM is the longer of the two lenses at 108mm. The Sigma 70mm F2.8 DG Macro with a length of 106mm, is 2mm shorter. Besides being longer, the Sony FE 85mm F1.4 GM also has a larger diameter of 90mm compared to the Sigma 70mm F2.8 DG Macro's 71mm diameter.
ss
Below you can find a scaled side-by-side image of Sony FE 85mm F1.4 GM and Sigma 70mm F2.8 DG Macro to get a better idea of how their sizes compare in real life.
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 70mm F2.8 DG Macro weighs 515g, 37% (305g) lighter than the Sony FE 85mm F1.4 GM's weight of 820g.
Filter Threads
The Sony FE 85mm F1.4 GM has a filter size of 77mm whereas the Sigma 70mm F2.8 DG Macro has a 49mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 77mm filters that we recommend you to consider for the Sony FE 85mm F1.4 GM:
And these are the 49mm filters that we recommend for the Sigma 70mm F2.8 DG Macro:
Lens Mounts
Both the Sony FE 85mm F1.4 GM and the Sigma 70mm F2.8 DG Macro has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony A9 III, Sony A7C Mark II and Sony A7CR.
Sigma 70mm F2.8 DG Macro is also available in Canon EF , Nikon F (FX) and Sigma SA mounts.
Focal Range
Sony FE 85mm F1.4 GM 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 70mm F2.8 DG Macro is a prime lens with fixed focal lenght of 70mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 105mm.