We can assess the RX100 IV's slow-motion video, however. Sony calls it High Frame Rate mode, complete with its own HFR spot on the shooting mode dial. In a menu, you select among capture rates of 240, 480, and 960 fps, then pick from file output frame rates of 24p, 30p, or 60p. By mixing these two options in different ways, you can slow motion by 4 to 40 times. You’re limited to capturing 2 sec of footage in Quality Priority mode or 4 sec in Shoot Time Priority mode. When shooting, you place the camera in standby first and then use the movie record button to start or end the shot. The camera buffers the footage and then renders it out in the video format you chose. You end up with a high-def video clip that’s much longer than the 2 or 4 seconds of motion you initially captured.