An opening that permits light to enter is called:

An opening that permits light to enter is called:

• A. Crack
• B. Vent
• C. Aperture
• D. Door

Answer: (C)

In optics, the opening through which light passes is called an aperture. It’s the adjustable gap in a lens or camera that light travels through to reach the sensor or film. The size of the aperture controls how much light enters and also influences depth of field: a larger aperture lets in more light and gives a shallower depth of field, while a smaller aperture lets in less light and yields a deeper depth of field. The other terms don’t fit as well because a crack is an irregular break, a vent is for air passage, and a door is a barrier for people rather than a light-transmitting opening.

In optics, the opening through which light passes is called an aperture. It’s the adjustable gap in a lens or camera that light travels through to reach the sensor or film. The size of the aperture controls how much light enters and also influences depth of field: a larger aperture lets in more light and gives a shallower depth of field, while a smaller aperture lets in less light and yields a deeper depth of field. The other terms don’t fit as well because a crack is an irregular break, a vent is for air passage, and a door is a barrier for people rather than a light-transmitting opening.