Daylight and night modes
Officers and staff working on the bridge are exposed to natural daylight during the day but are also in need of night vision light fittings when the vessels are operating at night. When a ship is docked in a harbour, daylight lux levels are required. This means that lighting on the bridge needs to simulate both daylight and night modes. The light output quality is important due to visual perception to enable the crew to distinguish between different colors and details. The colour-rendering index (CRI) should be above 80. Lux level should be around 150 lux in order to enable people to differentiate between colors and to view true colors. To avoid shadowing and reduce glare (UGR, unified glare ratio) a proper light calculation should be carried out. The colour temperature preferred on a bridge should be equal to or higher than 3000 Kelvin in order to improve safety during daylight levels. In addition, a dimmable red light mode is needed during night-time operations to ensure night vision capabilities.