I really love my GH3, but the 12-35 lens (while fabulous) isn't quite as wide as I'd like. I love using the Canon 17-40 on my 5D Mark III, and is much wider than the 24mm equivalent wide end of the 12-35. I went to my local BorrowLenses outlet and rented a Panny 7-14 to try it out on my GH3 for a few days ($45 for 3 days vs. $985 to buy it). I saddled it up on the CS8 (newly re-assembled with my repaired PDB and subtly re-wired to clean things up). Before getting into the IQ, I should note a couple things. First of all, this lens has no IS, which isn't really a big deal because of the very wide coverage. Secondly, and more importantly, there is no provision for any type of filter on the lens. This is potentially a show-stopper, as I've grown accustomed to using a ND filter for shooting video to attain a good exposure and shutter speed. The reason for this is the protruding front element (7mm is REALLY wide). Some super wide angle lenses have a drop in filter tray or other provision for this capability, but this lens doesn't seem to have anything like that. The other minor issue is that at 7mm, the FOV is so wide that the Cinestar's landing gear is in most shots! Now, as far as the IQ goes, it seems quite decent. I only did a couple quick flights, one with video and one with stills, and I neither balanced nor tuned the gimbal for the lens (it's slightly different than the 12-35). I was mostly flying just to test my CS8, which I just finished Humpty-Dumpty-ing after getting my PDB repaired. The video looks quite nice, although in retrospect, 7mm may be too wide to be practical. I may try again a 8-10mm. As for the stills, I am quite impressed. The camera was only shooting at 1/100 sec, as it was early in the morning and I had the ISO at 500. And, like I said, the gimbal wasn't tuned. But the lack of distortion and general sharpness seem quite nice. I've included a high-res JPEG here for your inspection. And it should be noted that, not surprisingly, the additional coverage allowed me to capture far more real estate at 60m in altitude than I can get at 100m with the 12-35. Will I go ahead and buy this lens? I think the answer at this point is "no". I'm not sure I need this wider FOV for video, and instead of spending nearly $1000, I can simply strap the 5DM3 onto the copter and take my stills. I think the 17-40 (or even the 16-35) is better quality at the end of the day, and the 5DM3 is a higher pixel count than the GH3, too. It seems the FF Forum's server can't handle a full-res JPEG, so here is a link to it from my website: http://perspectivair.com/images/2013-10-25-Aerial-2190.jpg. Here's the photo in low res.