If you know the FOV, sensor size, and working distance, you can compute the focal length of the lens you need using the following formula.

如果你知道视野FOV，感应器大小，和工作距离，你能用以下之方程序去计算你所需之镜头的焦距。

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A lens is primarily defined by its focal length. Figure 4 illustrates the relationship between the focal length of the lens, field of view, sensor size, and working distance.

一个镜头的基础定义是其焦距，图4图示出镜头焦距，视野，感应器大小，和工作距离间之关系。

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Two months before he died, newspapers were reporting that he was working on a "death ray," and that he had "killed a rat with an intricate device at a distance of three feet".

在他去世的两个月前，报纸报道称他正在研究“死亡射线”，并“用一个复杂的装置在三英尺外杀死了一只老鼠”。

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It has to be a bigger distance, a broader abyss, and that's what Iser is working with in the passages I'm about to quote.

它必须是一个更大的距离，更宽的深渊，这就是伊瑟尔在我想引用的那些话里面所试图说明的。

耶鲁公开课 - 文学理论导论课程节选

As you can tell from the cameras, the course is in fact filmed for reasons of distance education and your benefit for review; we've been working on this past summer what we dubbed cs50.tv which is our own delivery mechanism for these videos.

你们从大屏幕上可以看出来,该课程实际上是为远程教育拍摄的,你们能够在评论的过程中获益良多,今年夏天我们一直忙于cs50。tv网站的事,这样，拍摄完的视频就可以上传到这个网站。

哈佛公开课 - 计算机科学课程节选

"While Mitt Romney and Paul Ryan are working overtime to distance themselves from Rep. Todd Akin's comments on rape, they are contradicting their own records, " said an Obama campaign statement Monday.

CNN: Akin bows out of CNN appearance at the last minute

We are, for instance, committed to the Clinton Global Initiative and are working with UNICEF, the International Rescue Committee and Microsoft to launch an innovative new distance-learning program that provides supplementary education for 150, 000 displaced children and members of their host communities.

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Initially, the group was named Working Assets and was aimed at long-distance service.

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