研究人员必须解决的一个重要的 问题是，人眼的最小焦距是几厘米，无法分辨出隐形眼镜上显示的物体。

One major problem the researchers had to overcome was the fact that the human eye, with its minimum focal distance of several centimetres, cannot resolve objects on a contact lens.

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测算你相机的安全快门速度有一个好的方法，你相机镜头焦距的倒数，就是你避免镜头抖动的快门最小值。

A good rule of thumb to minimise camera shake is to set the shutter speed at a minimum of one second divided by your focal length.

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然后把摄像机内参数矩阵分解为有效焦距与主点位置两部分，并利用最小二乘法分别对其进行求解。

The intrinsic parameters are separated into two parts of focal length and coordinates for the principle point, which are then solved by using the least square method.

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