see also:

• Olympus Four Thirds dSLR system
• Four Thirds lenses
• standard camera zoom lenses
• Olympus website product info

• the initial version was the 1st pro quality standard camera zoom lenses for Olympus Four Thirds dSLR system which was then updated to this current Mark II version in 2009 coinciding with the release of the OlympusE30, which added high speed imager AF support for contrast detect AF in Live View mode
• a much loved lens
• see also Olympus ZD 12-60mm f/2.8-4.0 SWD zoom lens

• 14-54mm focal length = 28-108mm field of view coverage in 35mm terms
• f/2.8 (wide) - f/3.5(tele) to f/22
• weatherproofed
• 15 Elements in 11 Groups, 3 Aspherical lenses
• Floating & Internal Focusing System
• close focus 0.22m = 0.26x macro
• 7 circular blades
• 67mm filter
• 74.5 x 88.5mm
• 440g
• $549

• some vignetting at f/2.8 in extreme corners but less than the Leica;
• when compared to the Leica D 14-50mm (see here and open the pdf):
  • very similar performance but Zuiko has less vignetting and better corner resolution wide open at wide angle while the Leica has better corner resolution at wide angle at telephoto.
• SLRGear.com