In photography, the golden hour is the period of daytime shortly after sunrise or before sunset, during which daylight is redder and softer than when the sun is higher in the sky. The golden hour is also sometimes called the "magic hour," especially by cinematographers and photographers. During these times, the brightness of the sky matches the brightness of streetlights, signs, car headlights and lit windows. The period of time shortly before the magic hour at sunrise, or after it at sunset, is called the "blue hour". This is when the sun is at a significant depth below the horizon, when residual, indirect sunlight takes on a predominantly blue shade, and there are no sharp shadows because the sun either has not risen, or has set. Details When the sun is low above the horizon, sunlight rays must penetrate the atmosphere for a greater distance, reducing the intensity of the direct light, so that more of the illumination comes from indirect light from the sky, reducing the lighting ratio. This is technically a type of lighting diffusion. More blue light is scattered, so if the sun is present, its light appears more reddish. In addition, the sun's low angle above the horizon produces longer shadows. The term hour is used figuratively; the effect has no clearly defined duration and varies according to season and latitude. The character of the lighting is determined by the sun's altitude, and the time for the sun to move from the horizon to a specified altitude depends on a location's latitude and the time of year. In Los Angeles, California, at an hour after sunrise or an hour before sunset, the sun has an altitude of about 10–12°. For a location closer to the Equator, the same altitude is reached in less than an hour, and for a location farther from the equator, the altitude is reached in more than one hour. For a location sufficiently far from the equator, the sun may not reach an altitude of 10°, and the golden hour lasts for the entire day in certain seasons. In the middle of the day, the bright overhead sun can create strong highlights and dark shadows. The degree to which overexposure can occur varies because different types of film and digital cameras have different dynamic ranges. This harsh lighting problem is particularly important in portrait photography, where a fill flash is often necessary