The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 10-20mm F4-5.6 EX DC HSM and the Carl Zeiss Distagon T3,5/18 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 T3,5/18 is the longer of the two lenses at 84mm. The Sigma 10-20mm F4-5.6 EX DC HSM with a length of 81mm, is 3mm shorter. Besides being longer, the Carl Zeiss Distagon T3,5/18 also has a larger diameter of 87mm compared to the Sigma 10-20mm F4-5.6 EX DC HSM's 84mm 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.
Filter Threads
The Sigma 10-20mm F4-5.6 EX DC HSM has a filter size of 77mm whereas the Carl Zeiss Distagon T3,5/18 has a 82mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 77mm filters that we recommend you to consider for the Sigma 10-20mm F4-5.6 EX DC HSM:
And these are the 82mm filters that we recommend for the Carl Zeiss Distagon T3,5/18:
Lens Mounts
Both the Sigma 10-20mm F4-5.6 EX DC HSM and the Carl Zeiss Distagon T3,5/18 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 Mono, Pentax KF and Pentax K-3 III.
Sigma 10-20mm F4-5.6 EX DC HSM is also available in the Canon EF , Four Thirds, Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Carl Zeiss Distagon T3,5/18 is also available in Canon EF and Nikon F (FX) mounts.
Focal Range
Sigma 10-20mm F4-5.6 EX DC HSM has a focal range of 10-20mm and
2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
15-30mm when used on a APS-C / DX format camera.
On the other hand, the Carl Zeiss Distagon T3,5/18 is a prime lens with fixed focal lenght of 18mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 27mm.
