This page details three different Isocell sensors, including Bright, Fast, and Slim. It is unclear which sensor is used inside the Galaxy S9. Isocell Fast seems to be a potential candidate. Samsung's Isocell dual sensor, also mentioned on the page, may be outfitted with the Galaxy S9 +.
Isocell Bright uses Tetracell technology to improve low-light photography by combining four adjacent pixels into one large pixel. Samsung says Isocell Fast offers fast autofocus, even in low-light conditions. Samsung also talked about a new 3-layer fast readout sensor (FRS) on the page that captures high-speed full HD resolution. Samsung provided an example of full HD display at 480 fpsvideoRecord.
There have been recent rumors that the Galaxy S9 will have a new super-slow-motion video recording mode that identifies the camera as a "super-fast, two-pixel, 12-megapixel" camera with optical image stabilization and a flexible aperture. In the meantime, the Isocell Slim is a sensor that allows manufacturers to make slimmer cameras and smartphones. Samsung also sells its Isocell camera technology to other equipment manufacturers. Finally, Isocell Dual will provide users with "DSLR-like photo experiences, such as greater light perception, depth effects and brighter brightness in all situations."