Most lenses are at its best when stopped down by about three stops from their maximum aperture;

大多数镜头的最佳光圈是从它大光圈调细约三。

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Even if you intend to expose using a small aperture, a lens with a large maximum aperture can greatly increase viewfinder brightness.

即便你打算使用小光圈照相，带有最大光圈的镜头也可以在取景时大大增加取景器亮度。

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This is a technique called Maximum Aperture, and is done by adjusting the Settings on your digital camera to let more light pass through the lens.

这种技巧称为“最大光圈”，通过调整数码相机设置，让更多光线进入镜头，便可完成。

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The PENTAX MX-1 features a 4X optical zoom lens offering a large maximum aperture of F1.8 to F2.5 and 28mm wide-angle coverage (in the 35mm format).

ENGADGET: Pentax launches brass-bodied MX-1 point-and-shoot: 12MP with 4X zoom (update: now with hands-on photos)

This high performance, interchangeable zoom lens features an F2.8 maximum aperture throughout its entire 15-45mm zoom range and is designed for exclusive use with the PENTAX Q-Mount line of digital cameras.

ENGADGET: Pentax launches Q10 interchangeable lens camera, K-5 II and K-5 IIs flagship DSLRs

When set at maximum aperture and widest angle of view the photographer can use fast shutter speeds in dimly lit locations and take advantage of a beautiful bokeh (out-of-focus) effect in the background.

ENGADGET: Pentax launches brass-bodied MX-1 point-and-shoot: 12MP with 4X zoom (update: now with hands-on photos)