Quote Originally Posted by ME Super View Post
When not doing flash photography, there are four things that determine whether a scene will be properly exposed. They are:

  1. The amount of light falling on the scene (we'll call this Exposure Value (EV)).
  2. The sensitivity (ISO) of the film.
  3. The aperture (f/stop).
  4. The shutter speed.
Not to be pedantic, especially after your informative post, but I would add three more, for more advanced shooters

  1. Bellows factor
  2. Filter factor
  3. Reciprocity factor