The f-stop, otherwise known as the aperture, determines your depth of field (the area in focus) and how much light can pass through the lens to reach the sensor.

f制光圈(或称光圈)决定相机的景深(对焦区域)以及有多少光能通过镜头到达传感器。

youdao

Shall we stop down the lens?

我们要不要把光圈缩小一点?。

youdao

To study the structure of telecentric beam path for zoom lens system, the axial displacement equation for the stop was deduced, which keep the system telecentric in all zoom position.

进一步研究变焦距系统远心光路的结构特征，得出了使系统在整个变焦过程中都处于远心位置的光阑轴向位移方程。

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Other adapters can do some of that, but its final trick is the piece de resistance: increasing the speed of a lens by a full stop.

ENGADGET

Runco's cutting edge sward didn't stop there as they have this new projector screen-mask that when paired with the proper equipment and lens on Runco projectors can display any aspect ratio.

ENGADGET: Runco @ CEDIA - 1080p projectors HD