Excerpt: Bought this lens to use on a Blackmagic Design Studio Camera. There are very few lenses that actually work well on this camera. That is not the fault of this lens. The zoom works very nicely, but the focus is slow and not too accurate. The lens is not parfocal, so every zoom adjustment requires an adjustment of focus. Some of this is the camera...the lens is designed for still photography. A manual focus option would be useful.
Summary: I am a M43 panasonic user, I got a Olympus OMD E-M5 few months ago with the new Pro 12-40mm lens. I was impressed with some macro photographs I saw taken with this lens. I got a great price and did not hesitate to buy this sense from E-bay. I very happy with my results. I am using it with my GH3 as well.
Good lens that has become my primary walk around lens
1 November 2014
Summary: I purchased this as my primary walk around lens for my OM-D E-M5. While I own a Pan Lumix 14-42 (which is lighter and smaller) I wanted the weather seal the Oly provides along with the additional reach. This lens appears to fit my needs and I find the little extra boost it provides on both the short and long end useful. Before I list the drawbacks I want to say these were no surprise as most reviews clearly identify these shortcomings.
Summary: Bought this instead of the standard 14-42 kit lens and very happy I did. Great lens, no complaints. With the ISO capabilities of Olympus (OM-D E-M10 in my case) this lens is not as slow as reviews gripe about. It can produce some very pleasing bokeh and has an extremely versatile focal range. I have owned multiple systems and this is by far the versatile lens I have ever owned. I didn't expect to love this lens as much as I do.
Summary: This is a good all around lens, not super sharp like a prime, but has a good focal range. The Macro Mode is a plus, it is not 1:1 but with the x2 crop it gets you real close(I use macro rings to get even closer). I was on a budget and wanted a good multipurpose walk around lens.