Question Detail

The f-number is the ratio of focal length to aperture diameter: f-number = f/D. A smaller f-number means a larger aperture (D), which allows more light. f/1.6 has a larger aperture than f/16. So camera X (f/1.6) receives more light and requires a shorter exposure. Camera Y (f/16) has a smaller aperture, receives less light, and requires a larger exposure (or smaller exposure time). So camera Y has a smaller exposure? Actually, exposure is the amount of light per unit area. With a smaller aperture, less light reaches the sensor, so the exposure is smaller. So the correct statement is that camera Y has a smaller exposure.