iPhone 6 Plus introduces optical image stabilization that works with the A8 chip, gyroscope, and M8 motion coprocessor to measure motion data and provide precise lens movement to compensate for hand shake in lower light. The fusing together of long- and short-exposure images also helps to reduce subject motion. This unique integration of hardware and softwaredelivers beautiful low-light photos.
Keep in mind, though, that while apparently the iPhone 6 Plus does not use optical image stabilization for video recordings, it does use the excellent Cinematic Video Stabilization. This software algorithm is applied after you capture the video (that’s why there is a clear difference in the stability of recorded video as you see it in liveview in the camera, and after that – when you actually watch it from the Photos app), and it removes a lot of the nasty jittery effect. It may not be as stable as you get with optical stabilization, but the difference is not drastic either.