here http://blog.pchome.net/article/807122.html Let me make a brief translation. This is not a review, and the sample lens doesn't have a filter thread yet, which will probably be added on production model. This lens balances well on camera bodies like the Panasonic G7 without front heavy despite its full metal construction. The front element's coating reflects green cast (no mention of anti-flare capability); both the focus and stepless aperture rings are well damped, though they could be better off more separated. With the help of huge aperture and focus peaking on the G7, the combo managed to get good sharp low light shots in the Shanghai Museum of Natural History. At the wide open aperture it seems to be able to deliver quite sharp focus, without any sign of colour shifting issue often found on FF 50mm lenses, OOF areas are well rendered as well however some double lining can be found with busier backgrounds. Barrel distortions are there but the author suggests it's barely an issue on a lens like this for him when he can 1) keep the ISO low and still have sufficient shutter speeds and 2), get the beautiful bokeh which is comparable to a 50mm f/2 lens on a FF.