The type of photography that you are planning to use is an important decision factor. Here we have evaluated the HD Pentax-FA 35mm F2 AL and the Pentax FA 50mm F1.4 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. HD Pentax-FA 35mm F2 AL is the longer of the two lenses at 45mm. The Pentax FA 50mm F1.4 with a length of 38mm, is 7mm 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. HD Pentax-FA 35mm F2 AL weighs 193g, which means it is 27g (12%) lighter than the Pentax FA 50mm F1.4 which has a weight of 220g.
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
Both the HD Pentax-FA 35mm F2 AL and the Pentax FA 50mm F1.4 have the same Filter thread size of 49mm.
Below are links to the 49mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the HD Pentax-FA 35mm F2 AL and the Pentax FA 50mm F1.4 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.
Focal Range
HD Pentax-FA 35mm F2 AL is a prime lens with fixed focal lenght of 35mm which has an effective (full-frame 35mm equivalent) focal range of
52.5mm when used on a APS-C / DX format camera.
On the other hand, the 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.