Exposure - The 4 Factors

Exposure
There are 4 factors which regulate Exposure:

1. Amount of light.
The sun obviously produces more light than any bulb known to man. If the camera produces a image that looks normal under bright sunlight, it will - with the same setting - produce underexposure in a scene lit by a dim tungsten bulb.

2. Aperture.
The opening in the camera lens has the capability to block or admit light/ The narrower the aperture, less light enters the camera, thus creating dark images.

3. Shutter Speed.
The plate located between the lens an the camera recoding surface rotates at an adjustable speed and determines the time that each frame is exposed to light.

4. Recording surface sensitivity
The imaging device is the part of the camera that is hit by light(controlled by ISO). In a video camera, the recording surface is a CCD/CDMOS chip, where the image is first created. In a film camera, the recording surface is the actual film stock. When the CCD chip or film stock is sensitive to light then they are more likely to produce bright images with small amount of light.