|Closest Focusing||0.4 m|
|Max. Magnifcation||1:8.7 (0.115x)|
|Filter Size||55 mm|
|Diameter x Length||64 x 49 mm|
|Weight||295 gr (0.65 lb)|
This is an extremely light weight lens, definitely one of the lightest I've come across. Optical quality is good at f/5.6 and above. It actually holds its own against the thorium coated 35mm f/2.0, which I also tested. It is just slightly less sharp - just barely perceptible. The downside vs. that lens is that it is slower and harder to focus in low light. The upside is that it's tiny and almost too light to feel on your camera. It also flares less than the f/2.0.
Overall, this lens performs great if you stop it down slightly. Definitely worth looking at as an alternative to the 35mm f/2.0 if weight is an issue and big aperture is not.
Optical Test (using tripod, infinity focus):
Note: the following test was done on an APS-C sensor so corners are not considered.
At f/3.5: Chromatic abberation and less sharp.
At f/5.6 and above: Quite good sharpness, CA almost completely gone. Does not further sharpen past f/5.6 (at least in center).