F-stop The size of a lens opening.

She even remembers the aperture stop (lens opening) she used to obtain a particular effect more than 50 years ago.

There are two ways to do this: be more liberal in what's accepted as "sharp" and make the lens opening (aperture) smaller.

The clear lens opening was only 20 mm.

The largest lens opening (smallest f-number) at which the lens can be set.

The diaphragm functions much like the iris of the eye - it controls the effective diameter of the lens opening.

Numerical settings printed on the barrel of the lens, when selected, change the size of the lens opening; this is known as aperture.

He was always forgetting to put film in the camera or turn on lights or remove the cover from the lens opening.

The camera operator must have been newly recruited, because he fumbled for the correct lens opening.

For those who are unsure if a higher f-stop number means that more or less light is reaching the camera, an animation shows the size of the lens opening.