aperture

Everyday

1. (formal) An opening, hole or gap. tree →
2. (photography, science) The hole in a camera or telescope that lets light in; its size can be changed to let in more or less light. tree →

In the lessons

In science lessons on light, the aperture of a camera works like the pupil of your eye: wider in the dark, smaller in bright light. In photography, a big aperture blurs the background. In formal writing "aperture" can mean any narrow opening, like a gap in a castle wall. Phrases: a wide aperture, a narrow aperture, adjust the aperture.

Examples

• Light enters the camera through the aperture. tree →
• The pupil of your eye is like a camera's aperture. tree →
• Make the aperture smaller on a sunny day. tree →
• The cat squeezed through a narrow aperture in the fence. tree →
• Arrows were shot through apertures in the castle wall. tree →
• A telescope with a big aperture collects more light. tree →
• Delighted with his find he slipped in through the narrow aperture and greedily devoured it all. tree →

Note

Countable: an aperture (use "an"). Formal in the sense of "hole"; everyday speech says "hole" or "gap". Pronounced AP-er-cher.