The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax 21mm F3.2 AL L and the Olympus ED 14-42mm F3.5-5.6 EZ 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. Pentax 21mm F3.2 AL L is the longer of the two lenses at 25mm. The Olympus ED 14-42mm F3.5-5.6 EZ with a length of 23mm, is 2mm shorter. Besides being longer, the Pentax 21mm F3.2 AL L also has a larger diameter of 63mm compared to the Olympus ED 14-42mm F3.5-5.6 EZ's 61mm 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. Olympus ED 14-42mm F3.5-5.6 EZ weighs 91g, 35% (49g) lighter than the Pentax 21mm F3.2 AL L's weight of 140g.
Filter Threads
The Pentax 21mm F3.2 AL L has a filter size of 49mm whereas the Olympus ED 14-42mm F3.5-5.6 EZ has a 37mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 49mm filters that we recommend you to consider for the Pentax 21mm F3.2 AL L:
And these are the 37mm filters that we recommend for the Olympus ED 14-42mm F3.5-5.6 EZ:
Lens Mounts
The Pentax 21mm F3.2 AL L has the Pentax KAF lens mount whereas the Olympus ED 14-42mm F3.5-5.6 EZ has the Micro Four Thirds 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 KAF Mount and OM System OM-3 Astro, OM System OM-5 II and OM System OM-3 for the Micro Four Thirds Mount.
Pentax 21mm F3.2 AL L is also available in the Pentax KAF mount.
Focal Range
Pentax 21mm F3.2 AL L is a prime lens with fixed focal lenght of 21mm which has an effective (full-frame 35mm equivalent) focal range of
31.5mm when used on a APS-C / DX format camera.
On the other hand, the Olympus ED 14-42mm F3.5-5.6 EZ has a focal range of 14-42mm and 3.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 28-84mm when used on a FourThirds format camera.
