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 PENTAX15-30mm F2.8 ED WR 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. PENTAX15-30mm F2.8 ED WR is the longer of the two lenses at 144mm. The Irix 11mm F4 with a length of 118mm, is 26mm shorter. On the other hand, the Irix 11mm F4 has a larger diameter of 103mm compared to the PENTAX15-30mm F2.8 ED WR's 99mm 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. Irix 11mm F4 weighs 790g, which means it is 250g (24%) lighter than the PENTAX15-30mm F2.8 ED WR which has a weight of 1040g.
Lens Mounts
Both the Irix 11mm F4 and the PENTAX15-30mm F2.8 ED WR has the same Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with the Pentax KAF3 lenses are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III.
Irix 11mm F4 is also available in the 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 PENTAX15-30mm F2.8 ED WR has a focal range of 15-30mm and 2.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 22.5 - 45mm.
