The opening in a lens that controls how much light reaches the sensor, expressed as an f-number (f/2.8, f/8). Smaller f-numbers mean larger openings, more light and shallower depth of field.
The opening in a lens that controls how much light reaches the sensor, expressed as an f-number (f/2.8, f/8). Smaller f-numbers mean larger openings, more light and shallower depth of field.