The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony E 70-350mm F4.5-6.3 G 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. Sony E 70-350mm F4.5-6.3 G is the longer of the two lenses at 142mm. The Sigma 105mm F2.8 EX DG Macro with a length of 98mm, is 44mm shorter. Besides being longer, the Sony E 70-350mm F4.5-6.3 G also has a larger diameter of 77mm 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. Sigma 105mm F2.8 EX DG Macro weighs 460g, 26% (165g) lighter than the Sony E 70-350mm F4.5-6.3 G's weight of 625g.
Filter Threads
The Sony E 70-350mm F4.5-6.3 G has a filter size of 67mm 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 67mm filters that we recommend you to consider for the Sony E 70-350mm F4.5-6.3 G:
And these are the 62mm filters that we recommend for the Sigma 105mm F2.8 EX DG Macro:
Lens Mounts
The Sony E 70-350mm F4.5-6.3 G has the Sony E lens mount whereas the Sigma 105mm F2.8 EX DG Macro has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Sony ZV-E10 II, Sony A6700 and Sony FX30 for the Sony E Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Sigma 105mm F2.8 EX DG Macro is also available in Canon EF , Nikon F (FX), Sony Alpha, Sigma SA and Four Thirds mounts.
Focal Range
Sony E 70-350mm F4.5-6.3 G has a focal range of 70-350mm and
5.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
105-525mm when used on a APS-C / DX format camera.
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.