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
Both the Venus 25mm F2.8 2.5-5X Ultra Macro and the Voigtlander 20mm F3.5 SL II has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Venus 25mm F2.8 2.5-5X Ultra Macro is also available in Nikon F (DX) , Pentax KAF2 and Sony E mounts.
Voigtlander 20mm F3.5 SL II is also available in Nikon F (FX) 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 1.6x crop, it provides a 35mm (FF) equivalent of
40mm.
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 1.6x crop, it provides a 35mm (FF) equivalent of 32mm.