The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax 40mm F2.8 L and the Voigtlander 40mm F2 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 40mm F2 SL II is the longer of the two lenses at 25mm. The Pentax 40mm F2.8 L with a length of 15mm, is 10mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 63mm.
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 40mm F2.8 L weighs 80g, which means it is 120g (60%) lighter than the Voigtlander 40mm F2 SL II which has a weight of 200g.
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 40mm F2.8 L has a filter size of 49mm whereas the Voigtlander 40mm F2 SL II has a 52mm 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 40mm F2.8 L:
And these are the 52mm filters that we recommend for the Voigtlander 40mm F2 SL II:
Lens Mounts
Both the Pentax 40mm F2.8 L and the Voigtlander 40mm F2 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 40mm F2.8 L is also available in Pentax KAF mount.
Voigtlander 40mm F2 SL II is also available in Canon EF and Nikon F (FX) mounts.
Focal Range
Both lenses have the same focal range of
40mm but while Pentax 40mm F2.8 L has the fastest aperture of
F2.8, the Voigtlander 40mm F2 SL II's widest aperture value is
F2.0.