Light is the essence of photography.
To a great degree, the nature of the light helps to determine the mood or feel of a photograph. When we refer to the nature of the light, we are referring to its color, intensity and angle. Although we do not always see or recognize it with our eyes, light varies widely in its color and film is very sensitive to this color. Early morning and late afternoon light is usually described as being very warm, incorporating yellows and oranges. Shady areas tend to be described as having a cool blue light.