客变主未变，双反相机似廉颇老矣逐渐失去市场 曲高台者寡，３５ｍｍ相机欲小处着手未能此消彼长 尽管弗兰克和海得克公司把双反相机这个机种的工艺和性能似乎做到了极致，但到了本世纪的７０年代，它仍受到了来自两大方面的压力：一是１２０单反相机。１９４１年，瑞典人维可 Customer change has not changed, double-reverse camera is quite old and gradually lose the market song platform, widow, 35mm camera for the small office did not do the trickery Although Frank and the company has the Double-Reik camera this machine craft And performance seems to have done the most, but by the seventies of this century, it is still under pressure from two major aspects: First, 120 SLR cameras. In 1941, Swede Viktor