Question: what is the difference between shutter speed and f stop?
Answer: A: Aperture (f/stop) and shutter speed are both used to control the amount of light that reaches the film. ... f/4 allows half as much light as f/2.8. f/5.6 allows twice as much light as f/8). Shutter speed works similarly, but controls the amount of light reaching the film plane via the length of time the shutter is open.