What does it mean to increase the first level of exposure in photography?

Increasing one level of exposure in photography means adding one level to the original exposure set by the camera. In terms of specific operations, the purpose of increase can be achieved by changing any of the four items, aperture size, shutter speed, exposure compensation amount or ISO (sensitivity).

1. Increase the aperture by one stop (decrease the aperture value by one stop) and keep the other three items unchanged;

2. Increase the shutter time by 1 and keep the other three items unchanged;

3. The exposure compensation amount EV is increased by 1, and the other three items remain unchanged;

4. The ISO value is doubled, and the other three items remain unchanged.