The type of photography that you are planning to use is an important decision factor. Here we have evaluated the HD Pentax-DA 10-17mm F3.5-4.5 ED fisheye 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 HD Pentax-DA 10-17mm F3.5-4.5 ED fisheye with a length of 70mm, is 14mm shorter. Besides being longer, the Carl Zeiss Distagon T3,5/18 also has a larger diameter of 87mm compared to the HD Pentax-DA 10-17mm F3.5-4.5 ED fisheye's 68mm 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-DA 10-17mm F3.5-4.5 ED fisheye weighs 317g, which means it is 153g (32%) lighter than the Carl Zeiss Distagon T3,5/18 which has a weight of 470g.
Lens Mounts
Both the HD Pentax-DA 10-17mm F3.5-4.5 ED fisheye 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.
Carl Zeiss Distagon T3,5/18 is also available in Canon EF and Nikon F (FX) mounts.
Focal Range
HD Pentax-DA 10-17mm F3.5-4.5 ED fisheye has a focal range of 10-17mm and
1.7X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
15-25.5mm 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.
