That would put U.S. planes much closer to ISIS strongholds in Syria.

这将使美国飞机更接近ISIS在叙利亚的据点。

And when you get really close the plane of focus becomes extremely shallow… meaning only a small bit of your frame is in focus and everything else is blurry.

当你离得很近时，对焦平面会变得非常浅，这意味着只有一小部分画面是对焦的，其他的都是模糊的。