There are several threads about camera shake when using several 300mm lenses hand held. My recent testing has caused me to think IBIS may have some limits we could collectively develop a better understanding of. I was testing tripods (I'll post that later) & also tested to see how well I can hand hold my long teles & how much a monopod helps. The best I can reliably do handheld w/ the MZD 75-300 @ 300mm is 1/500". On a monopod, I can go down to 1/60". However, w/ the MZD 40-150 @ 150mm, I can hand hold down to 1/30 & adding the monopod does NOT improve things much. For all these tests, the OM-D is set to IS1 & Auto for focal length, Firmware is all current (v1.0 for the 75-300) & I was a competitive rifle shooter 45 yrs ago so I know how to hold steady though I'm certainly not a steady these dayshttps://www.mu-43.com/images/icons/icon10.gif. I was shooting a resolution target at close distances which makes getting good focus much harder but all the higher shutter speed images are sharp with the lens wide open. I examined RAW files but when there was shake, it was pretty obvious. This variation of relative performance seems to show the strengths & weaknesses of IBIS in its current implementation. But before reaching ANY conclusions, someone else needs to repeat these tests. Perhaps some of you have already or could take the time to do that. It would help us all out.https://www.mu-43.com/images/icons/icon4.gif Thanks much.