The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Panasonic 8-18mm F2.8-4.0 ASPH and the PENTAX28-105mm F3.5-5.6 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. Panasonic 8-18mm F2.8-4.0 ASPH is the longer of the two lenses at 88mm. The PENTAX28-105mm F3.5-5.6 WR with a length of 87mm, is 1mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 73mm.
Below you can find a scaled side-by-side image of Panasonic 8-18mm F2.8-4.0 ASPH and PENTAX28-105mm F3.5-5.6 WR to get a better idea of how their sizes compare in real life.
Comparison image of the Panasonic 8-18mm F2.8-4.0 ASPH and the PENTAX28-105mm F3.5-5.6 WR Size and Weight 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. Panasonic 8-18mm F2.8-4.0 ASPH weighs 315g, which means it is 125g (28%) lighter than the PENTAX28-105mm F3.5-5.6 WR which has a weight of 440g.
Filter Threads
The Panasonic 8-18mm F2.8-4.0 ASPH has a filter size of 67mm whereas the PENTAX28-105mm F3.5-5.6 WR has a 62mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Panasonic 8-18mm F2.8-4.0 ASPH:
And these are the 62mm filters that we recommend for the PENTAX28-105mm F3.5-5.6 WR:
Lens Mounts
The Panasonic 8-18mm F2.8-4.0 ASPH has the Micro Four Thirds lens mount whereas the PENTAX28-105mm F3.5-5.6 WR has the Pentax KAF3 lens mount . Some of the latest released cameras that are compatible with these mounts are OM System OM-3 Astro , OM System OM-5 II and OM System OM-3 for the Micro Four Thirds Mount and Pentax K-3 III Mono , Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount.
Focal Range
Panasonic 8-18mm F2.8-4.0 ASPH has a focal range of 8-18mm and
2.3X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
16-36mm when used on a FourThirds format camera.
On the other hand, the PENTAX28-105mm F3.5-5.6 WR has a focal range of 28-105mm and 3.8X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 42 - 157.5mm .
