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Question: I own a GH2 & am considering this lens for film purposes.  Know it doesn't have OIS, but how is quality when walking & filming? Any major jerkiness?
Document: I recently purchased aPanasonic Lumix DMC-GH2 16.05 MP Live MOS Interchangeable Lens Camera with 3-Inch  Free-Angle Touch Screen LCD (Black Body Only). The purchase was largely inspired by a desire for a smaller interchangeable lens camera for travel purposes. Since size was a major consideration I knew I wanted a fast, "pancake" prime to go with it.
As for video, the motor is too noisy when searching for focus and it goes in and out of focus while aimed at a subject.-Manually focusing should be used for video, but it has a learning curve. There are no exact measurements on the lens for focus racking, and on the GH2, there is a really poorly designed focus meter of how close and far you're focusing. I don't even know when I'm focusing at infinity or not!
The 20mm f 1.7 has proven to be the best addition investment I have spent money so far with my camera. The Voigtl&auml;nder 25mm f/0.95 for is the only faster one I know of and it's like 1000 bucks and hard to get. So for 320 smackers or so this lens is a STEAL. On a 2x crop sensor like my new GH2 its it takes amazing pictures very little distortion for a wide angle. Its quiet its fast it's cheap its built well.
With the GF1 + this pancake lens I have a small camera that I don't mind carrying and that takes DSLR-quality photos.It lacks OIS, but I don't really feel the need as this is a very fast lens.
After delaying getting this for years because I couldn't afford it, I finally bought it and I am SO glad I did. It is everything I hoped for. Fast, sharp, light. Great for hand-held night scenes and a find all-purpose walking around lens for a 4/3 system. I'm very happy with it and am not sure how I lived without it so long! Definitely fills a major niche in the prime lens collection.
Considering the unused space in the diameter of the lens and narrow compactness of the Olympus 45mm f/1.8 it shouldn't be difficult for Panasonic to create a smaller version of this lens especially if they want to continue to make smaller bodies as I'm sure they will.At $349, this lens is way overpriced. If this lens was $199 I could better accept the build quality, AF, and size of the lens.
Since I enjoyed the 50mm lens on a 35mm film body, I figured this 40mm-equivalent might come close. It is every bit as pleasing as the Pentax lens. In fact, I have to say that I actually like it more.The build quality is roughly what I expected. It isn't fantastic, but is adequate. It doesn't feel like it will break when I use it.The image quality is phenomenal! Corner to corner sharpness, vivid colors and excellent contrast are all found in this lens.
Even though it does have a frustrating manual and auto-focus mechanic, that should not sway you from the clarity and beautiful rendered bokeh it produces. Out of all of my lenses, this tiny 20mm f1.7 outperforms every one of my legacy glass in detailed image-quality. I have no idea why I've hesitated so long to get this lens, but this has become a very enjoyable experience and it will stay on my GH2 80 percent of the time.
The GH2 is a simple camera to use already, but with this lens the camera is as accessible as a point and shoot.The lens takes FANTASTIC quality in low-light! With the 14-140mm lens I struggled taking shots indoors with one source of overhead light. But this 20mm can't even tell the difference!I snagged mine on eBay on 4/15/2011 as the recent tsunami has businesses raising their prices --EXTORTING customers in some cases ($800? Really?
I'm really amazed. Digital is now better than any 35mm, we are in 6x7 quality now. I mean you can really crop. I have an adapter so I can use the few Nikon lenses I have left on the GF1, but this 20mm is definitely sharper. I feel sorry for you folks who are using the cheap Lumix zoom lens on your GF1s, you don't know what a fast sharp lens is like.
Answer: Sorry to take so long to respond.  I've only used this lens for video once, and it was on a very sturdy tripod.  A lens this short would probably cause little problems with shaky images in video.  If you already have the 14-to-140mm lens that the GH2 is usually shipped with, you already have 20mm focal length covered.  The only advantage to this lens is the larger aperture, which will allow for faster shutter speeds in still mode.  If you are shooting video indoors in available light, this lens might be worth the investment.  I shoot a lot of video and use a top quality tripod with an expensive video head for steady shooting and smooth panning.  The GH2 100-to-300mm lens with the GH2's built in optical teleconverter equates to a 1540mm telephoto lens in 35mm film!  At that length any vibration at all is magnified.  But anyway, I didn't buy the 20mm for use in video mode.  I'll do some testing and give you an update.