The Samsung Galaxy S7’s video recording has a few good strengths. It manages auto-exposure better than the iPhone 7 Plus, adjusting for brightness between different lighting situations. It’s able to focus faster and better in the dark than the 7 Plus, with less image noise. When shooting in good light, image detail, as well as colors look just as vibrant in videos from the S7 as from the 7 Plus.
Unfortunately, the S7’s fatal flaws remain: Obvious rolling shutter and lack of optical image stabilization (OIS). If you pan or move the S7 too quickly, videos wobble and shake like jelly. OIS is available when shooting Full-HD on both the S7 and the 7 Plus, but only available in 4K video on the 7 Plus. And these two strikes on image quality are enough to give the 7 Plus the lead in video.
The 7 Plus, like the 6s Plus, manage to avoid rolling shutter and deliver impressively smooth video with OIS. You can also zoom in and out while shooting video by tapping the ‘2x’ icon, but because the lens info isn’t embedded in the EXIF, I can’t tell if you actually are shooting with the 56mm when zooming or if it’s a cropped and enlarged image from the 28mm. Looking at how steady some 2x videos are, however, I have to suspect that the 7 Plus may default to the 28mm camera with OIS, when shooting videos that require stabilization.