The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Carl Zeiss Distagon T2,8/25 and the Sigma 24mm F1.8 EX DG 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 Sigma 24mm F1.8 EX DG with a length of 83mm, is 7mm shorter. On the other hand, the Sigma 24mm F1.8 EX DG has a larger diameter of 84mm 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. Carl Zeiss Distagon T2,8/25 weighs 480g, which means it is 20g (4%) lighter than the Sigma 24mm F1.8 EX DG which has a weight of 500g.
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
The Carl Zeiss Distagon T2,8/25 has a filter size of 58mm whereas the Sigma 24mm F1.8 EX DG has a 77mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 58mm filters that we recommend you to consider for the Carl Zeiss Distagon T2,8/25:
And these are the 77mm filters that we recommend for the Sigma 24mm F1.8 EX DG:
Lens Mounts
Both the Carl Zeiss Distagon T2,8/25 and the Sigma 24mm F1.8 EX DG 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.
Sigma 24mm F1.8 EX DG is also available in Canon EF , Nikon F (FX), Four Thirds, Pentax KAF, Sony Alpha, Sigma SA, Canon EF, Sony Alpha, Sigma SA and Nikon F (FX) mounts.
Focal Range
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.
On the other hand, the Sigma 24mm F1.8 EX DG is a prime lens with fixed focal lenght of 28mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 42mm.