The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Venus 25mm F2.8 2.5-5X Ultra Macro and the Voigtlander 20mm F3.5 SL II 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 25mm F2.8 2.5-5X Ultra Macro is the longer of the two lenses at 65mm. The Voigtlander 20mm F3.5 SL II with a length of 29mm, is 36mm shorter. Besides being longer, the Venus 25mm F2.8 2.5-5X Ultra Macro also has a larger diameter of 82mm compared to the Voigtlander 20mm F3.5 SL II's 63mm 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. Voigtlander 20mm F3.5 SL II weighs 205g, 48% (195g) lighter than the Venus 25mm F2.8 2.5-5X Ultra Macro's weight of 400g.
Lens Mounts
The Venus 25mm F2.8 2.5-5X Ultra Macro has the Nikon F (DX) lens mount whereas the Voigtlander 20mm F3.5 SL II has the Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (DX) Mount and Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount.
Venus 25mm F2.8 2.5-5X Ultra Macro is also available in Canon EF , Pentax KAF2 and Sony E mounts.
Voigtlander 20mm F3.5 SL II is also available in Canon EF and Pentax KAF mounts.
Focal Range
Venus 25mm F2.8 2.5-5X Ultra Macro is a prime lens with fixed focal lenght of 25mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
37.5mm.
On the other hand, the Voigtlander 20mm F3.5 SL II is a prime lens with fixed focal lenght of 20mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 30mm.