free working distance

例句：

1. 1.The camera is set up at a free working distance from the subject.
   相机设置在被摄体与镜头之间保持一定的自由工作距离。
2. 2. The teacher explained the concept of free working distance in detail.
   老师详细解释了自由工作距离的概念。
3. 3.In this project, we need to consider the free working distance between the camera and the subject.
   在这个项目中，我们需要考虑到相机和被摄体之间的自由工作距离。