Shutt er speed and exposure

To prevent a picture getting too bright or too dark when you change the shutter speed, the camera will adjust the aperture to maintain the same exposure. In the example above, you can see that setting a fast shutter speed of 1/800 sec (less light) results in a large aperture of f/2.8 (more light). Opting for a slower shutter speed of 1/13 sec (more light) forces the camera to pick a smaller aperture of f/22 (less light).