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The single-lens reflex (SLR) is a type of camera that uses a movable mirror placed between the lens and the film to project the image seen through the lens to a matte focusing screen. Most SLRs use a roof pentaprism or pentamirror to observe the image via an eyepiece, but there are also other finder arrangements, such as the waist-level finder or porro prisms.
Cross-section view of SLR system.The shutter in almost all contemporary SLRs sits just in front of the focal plane. If it does not, some other mechanism is required to ensure that no light reaches the film between exposures. For example, the Hasselblad 500C camera uses an auxiliary shutter blind in addition to its in-lens leaf shutter.
皆さん短時間に色々とご意見ありがとうございます。 私自身 デジカメより アナログに興味があり DARKROOMなどのクラスも取りたいと思っています。 将来的にそれでお金を稼ごうとするのであれば やはりデジカメに移ると思いますが 今の所はPHOTOGRAPHYを勉強したいと言う考えだけです。 クラスの内容はBlack and white film processing and printing techiniques とあるのでやっぱりアナログのカメラと言う事だと思います。