Now back in 2014, Apple announced that the iPhone 6 would have digital image stabilization, while the Plus would get optical image stabilization. As it turns out, this feature has been carried over to the iPhone 6s Plus as well. This means that if you were hoping that the iPhone 6s would get OIS, you will be disappointed.
It has also been discovered that OIS will now work with video, whereas previously it seemed more aimed at helping taking still images. For those wondering about the differences, basically DIS relies on software to help stabilize your camera to compensate for potential shakes. OIS on the other hand will rely on actual sensors built into the camera to offset any shakes while taking photos.
Other changes Apple has made includes bumping the resolution for panoramas to 63MP versus 43MP in previous iPhone models. The report also notes that pixel size has decreased from 1.5µ to 1.22µ, but hopefully it won’t be too obvious.