Sector light Authorities). For example, the United States uses a signalling stereotype which is the opposite of Europe. In USA, the red light indicates the starboard side of the channel for harbour bound vessels, while the green light indicates the port side of the same channel. An expression to remind of this is "red right returning". An example of a sector light is the light of the Fisgard Lighthouse in British Columbia. The lighthouse as built to guide ships through the entrance of Esquimalt harbour. The white sector is an isophase light of 2s from 322° to 195°. If the ship sees
Colour cast Colour cast A colour cast is a tint of a particular colour, usually unwanted, which affects the whole, or portion, of a photographic image evenly. Certain types of light can cause film and digital cameras to have a colour cast. Illuminating a subject with light sources of different colour temperatures will usually cause colour cast problems in the shadows. In general, the human eye does not notice the unnatural colour, because our eyes and brains adjust and compensate for different types of light in ways that cameras cannot. In film, colour casts can also be caused by problems in development.