Samsung Galaxy S5 Test of Low-Light 4K Video Performance
4K Video shot indoors in successively dimmer surroundings: From a reasonably lit library reading room, to windowless library rooms, to a dark window-lit dining hall, and finally to a windowless library illuminated by translucent marble and kept dim so that the marble shines, relatively. This last setting shows the limits of the Samsung.
Each building is preceded by outside shots so that the contrast, if any, of color and resolution can be easily made with the indoors shots by space.
All shots used a miniature tripod to prevent shake.
Video frame grab: