Conclusion: The Zuiko Digital ED 9-18mm 1:4-5.6 is without doubt a very good lens indeed, especially for a relatively inexpensive ultra-wideangle zoom. It's sharp even wide open, has negligible distortion, and shows practically no vignetting.
Pros: High image quality - decently sharp from centre to corner even wide open, Extremely low distortion, Essentially no falloff/vigmetting, Small and lightweight
Cons: Moderate chromatic aberration (although not excessive for an ultra-wide)
Excerpt: This compact ultra-wide angle zoom lens for Micro Four Thirds system cameras offers a 2x zoom range equivalent to an 18-36mm lens on a 35mm camera. It costs around £450 and sports a collapsible design.
Pros: Collapsible design, Lightweight, Fast, silent autofocus, Excellent sharpness in the centre of the frame throughout the zoom range, Low distortion, Good value compared to alternative
Cons: No lens hood supplied as standard, High CA levels towards the edges of the frame beyond 14mm, Prone to flare
Olympus M.Zuiko Digital 9-18mm f/4-5.6 ED - Review / Test Report
22 July 2012
Conclusion: The Olympus M.Zuiko 9-18mm f/4-5.6 ED is an engineering masterpiece. It is the most compact and light-weight ultra wide angle lens that we've reviewed to date. It is easy to use despite its small size and rather unusual retractable design.