It has a lens system to focus light onto the film at the back of the camera.

它的镜片系统可以将光线聚焦到相机后部的胶片上。

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If all these approaches are impractical, one could always resort to manual focus using distance markings on the lens.

如果这些方法都不奏效，你还可以利用镜头上的距离标示来手动对焦（以及合适的超焦距）。

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"The iPhone has a single-focus lens with no zoom, and this simplicity keeps me devoted to only composition and the perfect photo opp," Mitsui says.

三井说：“iPhone 3gs只有一个不能调焦距的镜头，这让我把注意力完全放在构图和最佳拍摄时机上。”

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It'd be hugely valuable to have the entire bottom of the screen act as a trigger, so you can focus on what's downrange of the lens instead of how to direct your fingernail to land on the speck-of-a-button that'll trigger the shutter.

ENGADGET: Nikon WU-1a wireless mobile adapter for D3200 review: using Android as a remote trigger / wireless display

Because many Blu-ray movies come in a 2.35:1 aspect ratio, which is wider than the projector's 16:9 aspect ratio, Panasonic's Intelligent Lens Memory automatically detects and switches the lens and focus position.

ENGADGET: Panasonic PT-AE8000U projector touts brighter, smoother 3D for king-of-the-hill home theaters