The type of photography that you are planning to use is an important decision factor. Here we have evaluated the OM System 12-40mm F2.8 PRO II and the Panasonic 8-18mm F2.8-4.0 ASPH 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 OM System 12-40mm F2.8 PRO II with a length of 84mm, is 4mm shorter. Besides being longer, the Panasonic 8-18mm F2.8-4.0 ASPH also has a larger diameter of 73mm compared to the OM System 12-40mm F2.8 PRO II's 70mm diameter.
Below you can find a scaled side-by-side image of OM System 12-40mm F2.8 PRO II and Panasonic 8-18mm F2.8-4.0 ASPH to get a better idea of how their sizes compare in real life.
Comparison image of the OM System 12-40mm F2.8 PRO II and the Panasonic 8-18mm F2.8-4.0 ASPH 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, 17% (67g) lighter than the OM System 12-40mm F2.8 PRO II's weight of 382g.
Filter Threads
The OM System 12-40mm F2.8 PRO II has a filter size of 62mm whereas the Panasonic 8-18mm F2.8-4.0 ASPH has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 62mm filters that we recommend you to consider for the OM System 12-40mm F2.8 PRO II:
And these are the 67mm filters that we recommend for the Panasonic 8-18mm F2.8-4.0 ASPH:
Lens Mounts
Both the OM System 12-40mm F2.8 PRO II and the Panasonic 8-18mm F2.8-4.0 ASPH has the same Micro Four Thirds lens mount . Some of the latest released cameras that are compatible with the Micro Four Thirds lenses are OM System OM-3 Astro , OM System OM-5 II and OM System OM-3 .
Focal Range
OM System 12-40mm F2.8 PRO II has a focal range of 12-40mm and
3.3X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
24-80mm when used on a FourThirds format camera.
On the other hand, the 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.