The type of photography that you are planning to use is an important decision factor. Here we have evaluated the HD Pentax-FA 31mm F1.8 Ltd and the Carl Zeiss Distagon T2,8/25 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. Carl Zeiss Distagon T2,8/25 is the longer of the two lenses at 90mm. The HD Pentax-FA 31mm F1.8 Ltd with a length of 69mm, is 21mm shorter. On the other hand, the HD Pentax-FA 31mm F1.8 Ltd has a larger diameter of 65mm compared to the Carl Zeiss Distagon T2,8/25's 64mm 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. HD Pentax-FA 31mm F1.8 Ltd weighs 341g, which means it is 139g (28%) lighter than the Carl Zeiss Distagon T2,8/25 which has a weight of 480g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Pentax KAF Mount for size comparison purposes.
Wideangle Lenses in Pentax KAF Mount for Size Comparison
Filter Threads
Both the HD Pentax-FA 31mm F1.8 Ltd and the Carl Zeiss Distagon T2,8/25 have the same Filter thread size of 58mm.
Below are links to the 58mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the HD Pentax-FA 31mm F1.8 Ltd and the Carl Zeiss Distagon T2,8/25 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.
Carl Zeiss Distagon T2,8/25 is also available in Nikon F (FX) mount.
Focal Range
HD Pentax-FA 31mm F1.8 Ltd is a prime lens with fixed focal lenght of 31mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
46.5mm.
On the other hand, the Carl Zeiss Distagon T2,8/25 is a prime lens with fixed focal lenght of 25mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 37.5mm.