One of the touted features of the new Oly OM-D E-M1 is improved AF with Oly 4/3 system lenses. Because Oly is offering a full rebate on the MMF-3 adapter when purchased with the E-M1, I decided to try the 50-200 SWD. It looked like a relatively cheap means of gaining some reach -- 100-400mm FX equivalency for under $700. So far, I think the combo looks like a keeper. Here are some handheld field test shots: 200mm, 1/320 @ 5 64mm, 1/50 at 3.2 169mm, 1/125 @4 130mm, 1/400@ 3.3 158mm, 1/2500 @4 200mm, 1/2000 @3.5 147mm, 1/320 @ 3.4 (crabapples up a tree) 200mm, 1/4000 @ 3.5 Please keep in mind that I've only had the camera two days and have adjusted only a few settings. Who knows, there may be room for improvement. :smile: The 50-200 SWD certainly isn't as quick to focus as an M43 lens like the 45 or 75. If you've pre-focussed near the subject distance, the 50-200 is pretty quick. But if the AF has to adjust for large distances, it's slow -- it sorta reminds me of when I had a D200/D70/50 driving an 80-200 AF-D or 180. I ran a very simple continuous AF test with cars moving towards me at a 25 degree angle. Shots had sharp focus for the first 10-12 shots of a burst and then sharpness dropped off. 1st shot, entire scene: 1st shot, 100%: 13th shot, 100%: When I get a chance, I hope to see how continuous AF fares with soccer. And, of course, I'd love to hear how others find their 4/3 lenses on the E-M1.