The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Irix 11mm F4 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. Irix 11mm F4 is the longer of the two lenses at 118mm. The Carl Zeiss Distagon T3,5/18 with a length of 84mm, is 34mm shorter. Besides being longer, the Irix 11mm F4 also has a larger diameter of 103mm compared to the Carl Zeiss Distagon T3,5/18's 87mm 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 T3,5/18 weighs 470g, 40% (320g) lighter than the Irix 11mm F4's weight of 790g.
Lens Mounts
The Irix 11mm F4 has the Pentax KAF3 lens mount whereas the Carl Zeiss Distagon T3,5/18 has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Irix 11mm F4 is also available in the Canon EF and Nikon F (FX) mounts.
Carl Zeiss Distagon T3,5/18 is also available in Canon EF and Nikon F (FX) mounts.
Focal Range
Irix 11mm F4 is a prime lens with fixed focal lenght of 11mm.
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.
