Haven't had a chance to do more than a couple minutes of testing, but I noticed yesterday when composing my first shots with the Rokinon 7.5mm FE on my E-M5, the stabilization was anything but. I have IS set to turn on with a half press of the shutter and I could certainly hear it whirring when I did just that, but it was as wobbly as a drunk leaving the bar he went to after getting fired from his job. I thought I somehow broke the IBIS on the camera, so I replaced the lens with the Oly 45 to check, but the IBIS worked like a charm again. Also, the resulting photos from the Roki were fine. I don't recall my shutter speed, except that it was more than adequate for a handheld shot. I know that I can turn IS off with a half press of the shutter, but as this is a manual focus lens, it would be prefereble to me to have a stable image in the viewfinder/screen with which to compose. I plan on checking it out again when I get home from work, but thought I'd chuck this out there now to see if anyone else has run into this issue. I can't possibly fathom how using that particular lens, or any lens for that matter, would cause this erratic behavior in my E-M5 IBIS. Thanks in advance for your help!