Summary: Extremely well built. Weatherproof. Excellent image quality. If there is a weak point, it would be focus speed. If Olympus would only come up with a camera that is worthy of their optical achievements...
Summary: While focusing is slow (under 3 sec) with AF-S/MF on an EM-5 or GH2, the resulting images are excellent. The TC 1.4X doesn't slow focusing and the images are plenty sharp @ F/4.5. The lens support ring is much needed when using this lens, especially with an m43 camera body. I also own the 50-200mm F/2.8-3.5 lens, and while it is optically less excellent than the 90-250mm lens, the significantly lighter and smaller 50-200mm lens gets a lot more use because it is so...
Summary: I purchased this lens shortly before a trip to Hawaii. It is very large and requires its own carrying bag. It is heavy so a tripod is almost a must; I have occasionally used it freehand but more often with a tripod or monopod. It provides outstanding sharp photos at long distances; with the f2.8 stopping action is great (surfers; shore objects from a ship a mile or two off shore).
Olympus 90-250mm f/2.8 PRO ED Zuiko Digital review by Ocean
31 July 2010
Summary: there is no better Zoom, I tested them all, even the Nikon 4/200-400 mm nor the Canon 5,6/100-400 mm can reach it. But the Olympus 2,8/300 mm is still sharper at f: 2,8. Its a little short, I would prefer it from 90-300 mm. But gone, Olympus should now create a 4,0/50-300 mm! But this Tele-Zoom is worth every cent!
Pros: best Tele-Zoom since today, full compatible with extenders and wide open
Summary: I USED IT ON AN OLYMPUS STAGE IN BERGAMO (PADANIA). IT'S UNBELIVABLE. A BIT HEAVY BUT INCREDIBLY SHARP FOR A 180-500MM (135MM). GOOD SATURATION AND BALANCE. FAST FOCUS EVEN IN LOW LIGHT (WITH E3) AND IN VERTICAL POSITION I REALLY COULDN'T FIND SOMETHING BAD EXCEPT FOR THE WEIGHT.