凸透镜焦点的确定、焦距的测量、成像特点的探究、成像特点的具体应用,是我们在学习这部分知识时要全面把握好的问题.对于这些问题,你把握的如何?一、焦距的测量例1小宇为了探究课堂上学到的透镜知识,用一个凸透镜和一张纸做实验.他把凸透镜放在太阳光底下,然后调整纸与凸透镜之间的距离,纸上得到一个最小、最亮的光斑,这时测 The determination of the focal point of the convex lens, the measurement of the focal length, the exploration of imaging features and the application of the imaging features are the questions that we must fully grasp when we study this part of knowledge. How can you grasp these problems? Xiaoyu explored the knowledge of lenses learned in class by experimenting with a convex lens and a piece of paper.He put the convex lens under the sunlight and then adjusted the distance between the paper and the convex lens to get the smallest and brightest paper Spot, then measured