single lens reflex (camera) (SLR)
SLR cameras are versatile, high-quality cameras used primarily in professional and semi-professional photography. This type of camera was the most advanced camera type for professional photography until the 1990s.
SLR cameras are available with interchangeable lenses, as single lens cameras, Single Lens Reflex(SLR), and as two lens cameras, Twin Lens Reflex (TLR). The digital SLR cameras, which have a high- resolution image sensor instead of film, are called Digital Single Lens Reflex( DSLR). The single lens system of SLR cameras is used for both object viewing and shooting. As can be seen from the name, SLR cameras work with a mirror system. The viewer sees the object to be photographed through the single-lens completely free of distortion, and as it will be photographed later.
The single lens is followed by a mirror system that tilts when the shutter is released, thus opening up the light channel to the film. This light channel is used to expose the film and, in the case of the digital SLR camera, the image sensor.