上世纪二三十年代,以Korelle 120和Exakta(中文一般译作爱克山泰)127等为代表的中片幅单镜头反光相机技术已经较为成熟,但仍因体积稍大、片幅较少等制约着摄影的普及。德国徕兹(Leitz)公司等厂商研制的135旁轴相机虽说体积轻盈、便于携带,但缺乏单镜头反光相机的无视差、可直接使用多种附件、更换特殊镜头等优势。因此,制造一台集上述两种相机优点于一身的小型单镜头反光相机就成了市 In the 1920s and 1930s, the medium-format single-lens reflex camera technology represented by Korelle 120 and Exakta (Chinese general translation Aiketai Tai) 127 has been relatively mature, but due to its larger size and smaller size Restricting the popularity of photography. 135 paraxial cameras developed by companies such as Leitz in Germany are lightweight and portable. However, the lack of parallax in single-lens reflex cameras makes it easy to use a variety of accessories and replace special lenses. So, creating a small, single-lens reflex camera that combines the advantages of both cameras has become a