彩扩镜头的设计与选购（二）文钟伯亮二、如何选择纯头的结构型式在确定了彩扩镜头的焦距后，对同一焦距，市场上往往有各种结构型式的镜头，价格相差很大。对设计者来说，在为某一种型号的彩扩机设计配套镜头时，也往往需要确定初始的结构型式。镜头的结构型式是由以下两... Second, how to choose the structure of the pure head type In the determination of the focal length of the expanded lens, the same focal length, the market often have a variety of structural types of lenses, the price difference between the very large . For designers, the design of a particular type of Caikuo machine supporting lens, often also need to determine the initial structure. The structure of the lens is composed of the following two ...