The Sony Alpha A7R II supports a maximum video resolution of 3840 x 2160 pixels. That's over four times the video resolution of a 1920 x 1080 pixels camera, which is the most common video resolution supported by MILC cameras that came out in the last 12 months. 1920 x 1080 pixels is also supported by this camera. In addition, this Sony camera supports a video resolution of 1280 x 720 pixels. A video resolution of 3840 x 2160 pixels is equivalent to 4K Ultra HD video. This has four times the detail of Full HD video.
A 3840 x 2160 pixels video resolution is actually the best supported video resolution amongst all digital cameras that have been on the market for around the same time as the Alpha A7R II.
A 640 x 480 pixels video resolution is the worst supported video resolution amongst comparable types of digital camera.