The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Venus 100mm F2.8 2X Ultra Macro 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. 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, 27% (178g) lighter than the Venus 100mm F2.8 2X Ultra Macro's weight of 638g.
Filter Threads
The Venus 100mm F2.8 2X Ultra Macro 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 Venus 100mm F2.8 2X Ultra Macro:
And these are the 62mm filters that we recommend for the Sigma 105mm F2.8 EX DG Macro:
Lens Mounts
The Venus 100mm F2.8 2X Ultra Macro has the Pentax KAF2 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 Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF2 Mount and Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Venus 100mm F2.8 2X Ultra Macro is also available in Canon EF , Nikon F (FX) and Sony E mounts.
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
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.
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.