And mathematically, you can express that in terms of how much that object subtends.

从数学 上讲，可以用该对象对向程度来表达这一点。

An object is said to subtend a certain angle of your vision based on how close you are to it, and how big it is.

根据 与接近程度以及大小，据说一个物体对着野某个角度。

So if you look at our tiny leaf, it may subtend only two degrees of your vision when it’s at your near point – say, 25 centimeters away.

所以果看着我们小叶子，当近点——比 25 厘米远——时，可能只对着两度线。

The original subtended angle is the subtended angle of the unaided eye – the angle between the center of the objective lens and the height of the real image.

原对角是肉眼对角——物镜中心与实像高度夹角。

But when you look at the leaf through the lens, the virtual image is larger than the actual object, so it subtends six degrees of your vision.

但是当通过镜头看树叶时 ，虚像比实际物体大， 所以对着线六度。

In order to find the magnifying power of the lens, you just divide the angle subtended by the virtual image by the angle subtended by your unaided eye.

为了求出镜片放大倍率 ，只需用虚 像对角除以肉眼对角。

So if you look at our tiny leaf, it may subtend only two degrees of your vision when it's at your near point – say, 25 centimeters away. .

因此，果看我们小叶子， 当近点（例 25 厘米远）时，可能只对着线两度。

We have the magnification equation, expressed in terms of subtended angles, but we can still use the equations in terms of distance and height for both objects and images.

我们有放大方程， 用对角表示，但我们仍然可以使用物体和图像距离和高度方程。

And the newly subtended angle is the amount that the object subtends when viewed through the eyepiece – the angle between your eye and the rays from the eyepiece.

新对向角是通过目镜观察物体时对向量——眼睛与目镜发出光线之间角度。

For example, if you’re looking up at the moon, and you cover it with your thumb, then your thumb and the moon are both subtending the same angle to your eye, which we measure in degrees.

例，果正抬头看月亮，并用拇指遮住，那么拇指和月亮都会与眼睛形成相同角度，我们以度为单位进行测量。

For example, if you're looking up at the moon, and you cover it with your thumb, then your thumb and the moon are both subtending the same angle to your eye, which we measure in degrees.

例，果抬头看着月亮，然后用拇指遮住，那么拇指和月亮都对着眼睛，我们用度数来衡量这个角度。