What is a single-lens reflex (SLR)?
The single lens reflex (SLR) is most folks’ idea of a serious camera. “SLR” means that the same lens is used for viewing and taking pictures. A mirror in the body directs the light from the lens up into a prism for viewing, then flips up out of the way just before an exposure is made. The standard photojournalist’s Nikon from the 1960s or 1970s was an SLR with a roll of 35mm film behind the mirror. When the mirror came up the light passed through to the shutter, which opened to expose one frame of film for perhaps 1/60th of a second. A Canon Digital Rebel or Nikon D80 looks very similar and works in almost the same way. The only difference is that instead of a piece of film behind the shutter there is an electronic sensor. The mirror and optical viewfinder are what enable a photographer to frame images more quickly and accurately than with a point-and-shoot camera. Regardless of what lens or filters you have attached to the camera you see what the sensor will see. The same can be said
