Olympus m.ZD 17mm f/2.8 pancake lens

introduction

one of the 1st Olympus Micro Four Thirds lenses to be produced and thus has an older, slower AF mechanism and the optic quality is very average for a prime lens although central sharpness is very good.
very compact, cheaper and with nicer bokeh than the legendary Panasonic Lumix 20mm f/1.7 pancake lens but obviously is f/2.8 rather than f/1.7
users should consider the cheap but excellent Sigma 19mm f/2.8 EX DN asph lens for Micro Four Thirds as an alternative to this lens
although I own this lens, personally I would not advise users to buy it - get one of the above lenses instead
only slight (0.8%) barrel distortion when corrected by Olympus cameras but RAW distortion is quite bad at 4.5%
vignetting is mild at 0.8EV
substantial CA which is uncorrected (2.2px at f/2.8 increasing to 2.8px at f/5.6, and averages 3px at the edges)
prone to lens flare without a hood when shooting into bright lights
very sharp in the centre but borders only average and best at f/4 while corners are soft wide open and reach average at f/5.6

17mm focal length = 34mm in 35mm film terms = very nice for street photography
f/2.8-f/22 aperture = an almost an extra stop light and DOF performance compared to the kit lenses
37mm filter size - same as the Olympus m.ZD 45mm f/1.8 portrait lens and the Olympus 14-42mm f/3.5-5.6 IIR
closest focus 20cm
lens extends slightly when powered up
6 elements in 4 groups = high optical quality with reasonable bokeh
71g
57mm x 22mm long (pancake)