Definitions:

1. The ratio that measures the size of a camera lens's aperture. NOUN
   • Adjusting the f-number on your camera affects both the exposure and depth of field of your photographs.
2. Used in photography to indicate the amount of light that passes through the lens of a camera. NOUN
   • A lower f-number, such as f/2, means a larger aperture, allowing more light to hit the camera sensor, ideal for low-light conditions.

Synonyms:

• f-ratio
• F-stop
• stop number