The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax FA 50mm F1.4 and the Voigtlander 58mm F1.4 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. Voigtlander 58mm F1.4 SL II is the longer of the two lenses at 48mm. The Pentax FA 50mm F1.4 with a length of 38mm, is 10mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 64mm.
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. Pentax FA 50mm F1.4 weighs 220g, which means it is 100g (31%) lighter than the Voigtlander 58mm F1.4 SL II which has a weight of 320g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Pentax KAF Mount for size comparison purposes.
Standard Lenses in Pentax KAF Mount for Size Comparison
Filter Threads
The Pentax FA 50mm F1.4 has a filter size of 49mm whereas the Voigtlander 58mm F1.4 SL II has a 58mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 49mm filters that we recommend you to consider for the Pentax FA 50mm F1.4:
And these are the 58mm filters that we recommend for the Voigtlander 58mm F1.4 SL II:
Lens Mounts
Both the Pentax FA 50mm F1.4 and the Voigtlander 58mm F1.4 SL II 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 Monochrome, Pentax KF and Pentax K-3 III.
Pentax FA 50mm F1.4 is also available in Pentax KAF mount.
Voigtlander 58mm F1.4 SL II is also available in Nikon F (FX) mount.
Focal Range
Pentax FA 50mm F1.4 is a prime lens with fixed focal lenght of 50mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
75mm.
On the other hand, the Voigtlander 58mm F1.4 SL II is a prime lens with fixed focal lenght of 58mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 87mm.