The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Voigtlander 20mm F3.5 SL II and the Pentax 10-17mm F3.5-4.5 ED Fisheye 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. Pentax 10-17mm F3.5-4.5 ED Fisheye is the longer of the two lenses at 72mm. The Voigtlander 20mm F3.5 SL II with a length of 29mm, is 43mm shorter. Besides being longer, the Pentax 10-17mm F3.5-4.5 ED Fisheye also has a larger diameter of 68mm 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, which means it is 115g (35%) lighter than the Pentax 10-17mm F3.5-4.5 ED Fisheye which has a weight of 320g.
Lens Mounts
Both the Voigtlander 20mm F3.5 SL II and the Pentax 10-17mm F3.5-4.5 ED Fisheye has the same Pentax KAF lens mount. Some of the latest released cameras that are compatible with the Pentax KAF lenses are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III.
Voigtlander 20mm F3.5 SL II is also available in the Canon EF and Nikon F (FX) mounts.
Focal Range
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.
On the other hand, the Pentax 10-17mm F3.5-4.5 ED Fisheye has a focal range of 10-17mm and 1.7X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 15-25.5mm when used on a APS-C / DX format camera.
