Measuring the Intensity of Light

In order to shoot an image with the correct exposure, you have to know the correct value of the intensity of light. Photographers use light meters to measure the intensity of the reflective light in a scene. Digital cameras have built-in light meters that are very sophisticated and incredibly accurate. However, their accuracy is subjective. The recommended aperture and shutter values are determined by how light falls in the scene and by how the light meter is set.