Review by Klaus Schroiff, published February 2009

Introduction

The Panasonic lens is very compact although it's not a magnitude smaller than e.g. the Canon EF 55-250mm f/4-5.6 IS (an APS-C lens with the same field-of-view). The build quality is very fine thanks to very tight tolerances, good quality plastics and a stainless steel mount. The rubberized zoom and focus control ring operate very smooth. The fluted rubber rings have a downside though - they tend to collect dust (similar to the 14-45mm f/3.5-5.6). The lens extends when zooming towards the long end of the zoom range but there's no wobbling of the inner lens tube. The front-element does not rotate during focusing so it remains possible to use a polarizer (without attached hood).

Typical for all 4/3 lenses the Panasonic lens uses a dedicated AF motor that operates quite fast and virtually silent. Thanks to the contrast AF system of the G1 the AF accuracy is high (from a lens perspective). Manual focusing is possible "by wire" which worked just fine during the field tests. Olympus lenses rely on the in-camera image stabilization system whereas Leica/Panasonic follow a lens-based solution called "Mega OIS" (Optical Image Stabilization). In field conditions OIS is able to give you a 2-3 f-stop extra potential for hand-held photography. It is a bit odd that the OIS remains always "on" even in non-stabilizing mode - we have seen a similar behavior with the Sigma 18-125mm f/3.8-5.6 OS HSM lately. Optically this doesn't seem to have any impact but it causes some power drain which is not overly desirable. That said most users will keep the OIS activated anyway so it's a bit of a phantom pain here.