Nathan, I usually start out maxed at 300mm but adjust as needed. I did shoot with an Olympus OMD-EM1 but only had the 12-40 zoom. I tried action shots in low light and it just wasn't fast or accurate enough for my needs. I never tried a longer lens or daylight action shots so I can't make a comparison. What I can say is the V3 70-300cx combo is pretty amazing for its size, reach and IQ in good light. As light goes down so does quality. Hope this helps.