在人教版《自然》第十二册《凸透镜》一课中,有个关于“土照像机”的制作,它能很好地让学生理解凸透镜成像的作用及其在生活中的应用。按照书中图示,我们也制作了一个。但在使用中发现,当观测者所处环境较亮时,几乎就看不清凸透镜在“底片”上所成的像了。为此,我们设计了一个带遮光罩的“土照像机”,它很好地解决了前面所遇到的问题。带遮光罩的“土照像机”由机身和观测窗两部分组成。 In PEP 12, entitled “Convex Lens”, there is a book on “Soil Camera”, which can well help students understand the function of convex lens imaging and its application in life. According to the book icon, we also made one. However, in use, it is found that when the observer is in a bright environment, the image formed by the convex lens on the “negative film” can hardly be seen. For this reason, we designed a “dirt camera” with a hood, which solved the problems encountered in the past. With a hood “soil camera” by the fuselage and observation window of two parts.