I have read dozens of articles and have tried to narrow it down. But I think after much work the effect is reduced but still there in parts. I have balanced the props, much better. Checked the props attack angle across the body of the drone and within a mm they are level. Took it out today for a test flight. It is better but still there in parts. If the drone is going into the wind, 12-16mph gusts today, it seems to happen more. I am going to download a video of the flight below but it does demonstrate how varied the problem is. At 1:24, 1:40 & 2:35 its quite noticeable. Yet if you goto 2:57-3.43 its quite still 5:51-6:18 the same. I dont think its the gimbal as the drone is rock steady when heli is still. 1280p 25fps Iso 100. Automatic set for clouds. That's more or less the settings. Would increasing the frame rate help and say fitting a filter? CPL perhaps? Suggestions welcomed. Video below when its finished uploading.