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 Venus 100mm F2.8 2X Ultra 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. Venus 100mm F2.8 2X Ultra Macro is the longer of the two lenses at 125mm. The Sigma 105mm F2.8 EX DG Macro with a length of 98mm, is 27mm shorter. On the other hand, the Sigma 105mm F2.8 EX DG Macro has a larger diameter of 74mm compared to the Venus 100mm F2.8 2X Ultra Macro's 72mm 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, which means it is 178g (27%) lighter than the Venus 100mm F2.8 2X Ultra Macro which has a weight of 638g.
Filter Threads
The Sigma 105mm F2.8 EX DG Macro has a filter size of 62mm whereas the Venus 100mm F2.8 2X Ultra Macro has a 67mm 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 67mm filters that we recommend for the Venus 100mm F2.8 2X Ultra Macro:
Lens Mounts
The Sigma 105mm F2.8 EX DG Macro has the Pentax KAF lens mount whereas the Venus 100mm F2.8 2X Ultra Macro has the Pentax KAF2 lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF Mount and Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF2 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.
Venus 100mm F2.8 2X Ultra Macro is also available in Canon EF , Nikon F (FX) and Sony E 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 1.5x crop, it provides a 35mm (FF) equivalent of
157.5mm.
On the other hand, the Venus 100mm F2.8 2X Ultra Macro is a prime lens with fixed focal lenght of 100mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 150mm.