Dimension 35mm f/2.8

Image and build quality I use it with shooting video on Lumix GH4. It is a very good lens in terms of build quality (with some notices), image quality and optical stabilization. Sharp image makes it plenty for DMC-GH4 detailed picture. Wide open f2.8 aperture allows to blur out background in pretty good amount. Also I don't see any chromatic aberration. Focusing and zoom rings are pretty smooth. It is no problem with manual focusing on this lens if you have some skill (and camera focus peaking). For me first lens disadvantage is the thin rubber water resist ring on the back side. Strong rain drops are penetrate deep into camera. Second (and not so important for me) is non-parfocal lens. Very good choice for this price.

Nice, fast, sharp & lightweight. This lens compliments the Panasonic GH series quite well. I shoot video with the Panasonic Lumix GH3 and this 12-25mm lens is a great lens to own. It's compact in size and has a very durable build to it. Both the zoom and focus rings are extremely smooth. With a built in OIS (image stabilizer), handheld shooting delivers an incredible steady shot (within reason of course). I discovered the secret ingredient to achieving such a clean and crisp image with this lens paired with the GH3 is as follows: (With good to excellent lighting) In Video Mode: 1. Set the camera (GH3) to "High" iDynamic and "High" iResolution 2. Set the image profile to "Standard" using -5 contrast, -2 sharpness, 0 saturation, -5 noise reduction 3. Use a f/2.8 aperture 4. Use aperture priority in menu selection (camera will auto set shutter speed and ISO) in good lighting the auto ISO settings work great. I typically shoot 24p 72Mbps ALL-INTRA MOV But I suggest you use your discretion as to the Recording Quality that appeals to you best for your needs. ***Please note that these settings work best when shooting people at a close to reasonable distance. These settings yield a very sharp/crisp image and shooting too far away from the subject will lead to unwanted aliasing and moire effects. If you are looking for a less sharpened image, i suggest not using the "High" iDyanmic & "High" iResolution settings. Or, use color grading techniques that will soften the image in post production if you use the "High" settings. All in all, this lens is great for videos and photos. I recommend you own this lens if you have a GH series camera.Read full review

Great All around Lens! Could be better with the f stop limitation. The range is perfect for m43 format, and the f/2.8 aperture helps is lower light setups. The image is clean, no obvious visible chromatic aberrations. The lens maintains a great geometry throughout the range. Pretty good for video too, it focuses really fast and the zoom range associated with the crop factor makes it an excellent lens for handheld operations. The bonus is the OIS, it does help smooth out micro shakes. Improvements: I wish Panasonic and Olympus could be a bit more up to date with people's needs. An f/1.8 or f/1.4 constant aperture, parfocal zoom lens with OIS is what most dslr videographers and event photographers would call an amazing and versatile low light lens.. Until the day when Panasonic and Olympus would rival 5D MKIII and an at least 10% or The A7s usable high iso range there will always be a group of unhappy M43 users... 12-35mm f1.8 with OIS would have been greater than any of the lenses Panasonic and Olympus have been providing to their loyal customer at heavy prices. If sigma can do it, why can't they?Read full review