Correct exposure is essential for good photographs.
Whether you use a digital or film camera, getting the correct exposure is essential for good photographs. Simply put, exposure refers to how much light is reaching the film or the image sensor on digital cameras. To determine the correct exposure, you need to have the right combination of shutter speed and F-stop. Shutter speed is how long the shutter is open, allowing light into the camera. F-stop tells you the size of the aperture, which is the hole light passes through in the camera.
Instructions
1. Measure the light of the scene you want to shoot. Use a light meter, which will return a combination of shutter speed and F-stop, or set your camera to "auto," depress the shutter halfway and note the speed and F-stop the camera chooses. For example, you might see a reading of F/8 at 1/125th of a second.
2. Choose the F-stop you desire. The larger F-stop numbers actually indicate smaller aperture size. Different aperture sizes, in turn, create different looks in a photograph. For example, a larger aperture will cause more of the background to be out of focus. The standard series of F-stops on most cameras is F/1.4, F/ 2.0, F/2.8, F/4, F/5.6, F/8, F/11, F/16, F/22, F/32, F/45 and F/64. Each step along the series (or "stop" as photographers say) allows in half the light as the setting before it. Perhaps you choose to go one "stop" down in aperture size and change the F-stop from F/8 to F/11, allowing in only half the amount of light.
3. Adjust the shutter speed to compensate for the change in F-stop. As with F-stop, each step in the series of shutter speeds allows in half as much light as the previous step. Measured in seconds, the series progresses to fractions of seconds (with a bit of rounding as the times get shorter): 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000 etc. In this example, the aperture went from F/8 to F/11 allowing in only half as much light. Therefore, you must adjust the shutter speed from 1/125th to 1/60th of a second, allowing twice as much time for light to enter. Similarly, changing the F-stop two stops down to F/16 would require a shutter speed of 1/30th of a second, two stops up from 1/125.
Tags: shutter speed, much light, speed F-stop, allowing only, allowing only half, allows half
