Hi all, I posted this over on DPR but I struggle with their archaic thread system and also have had a few answers so thought I'd post here to update and for those that don't use DPR. Its a rainy day here so I thought I'd do some testing on the image stabilising options of the new PL100-400 mounted to an Olympus EM1. It's a simple test, in a neighbours garden is an old birdbox on a pine tree that had the top cut off, I often use it for a target for testing telephoto lenses. How slow can I go? All shots handheld @ 400mm, shutter priority and auto-iso, I just wanted control of shutter speed. I started with all stabilisation switched off and at 1/800 and took 10 shots (refocussing each time) then repeat at 1/400, then 1/200, then 1/100, this will give a benchmark of how stable my hands are. I then switched on the IBIS (Half way Rls with IS = ON) and went from 1/200 down until images seemed blurry in the VF @ 1/50. I then flipped the POIS switch on the lens so I believe in effect both are working, I can't confirm this or otherwise but both lens OIS and camera IBIS where whirring. This is likely how it would be if you had just bought the lens and put it on your EM1 without changing any settings. Starting at where I left off with just IBIS I did 1/50 and 1/30, seemed cheeky to go any lower.. UPDATE - it seems the switch on the lens controls the IBIS too, so you can do the test simply by flipping the switch on the lens. I then switched off IBIS so just OIS working and repeated 1/50 and 1/30. Then I looked through each shot and rated them Sharp, Marginal and Blurry. Sharp is sharp to super-sharp (no obvious blur @ 200% but focus/ISO changes might cause varience), Marginal is where there might be a touch of blur but I would have kept the shot if it were interesting and the only choice, blurry ranges from just a bit too blurry to use to woooah! This is a bit subjective but I tried to keep judging the same, no doubt other's marginal calls would be different. The results can be seen in the table below with a shot of the test target (1/30, f/9, ISO200). From this limited testing my conclusions are: 1) IBIS alone struggles with this long a focal length. It seems fine with the 150mm of the pro zoom though - I can get a decent keeper rate at 1/15s - but that may be the FL limits of IBIS. 2) POIS is great and gets a very high keeper rate down to 1/30 which is more than enough for any situation where you might use an 800mm EFL lens, I should probably test slower than 1/30 but in reality I would never use it as subject motion blur would become a big factor. 3) I am happy to use it with both IBIS and POIS on, I can't say for sure if it is better than POIS on its own but it which means less faffing around in settings which I'm all for. This is how I will leave the settings. UPDATE - as above, it seems like the switch on the lens controls the IBIS too so you have one or the other, I like this. Hope that's of use to some people trying to make a call about this lens on an Oly body. UPDATE - you can view 'Both' and POIS as replications of the same settings, which shows good consistency.