How Do SLR Cameras Work?
The Basics Single-lens reflex cameras were a major innovation in camera design because the photographer can see the same thing the film will capture. Previous camera designs, including twin-lens reflex, rangefinder and point-and-shoot cameras, all had separate “taking” and “viewing” lenses. This meant there always would be at least a slight difference between what you saw and what was recorded on film. It also prevented the use of extreme wide-angle or telephoto lenses. The SLR fixed all this by using a single lens. The “Magic” Pentaprism Pentax introduced the SLR in the late 1950s, as did Miranda. Pentax derived its name from the pentaprism that makes the SLR work. Essentially, this is a prism with five sides that takes the image and turns it right-side up and changes it from left to right so the eye-level view is the same as you would see it with your eye. Originally, before the pentaprism, the image was reversed left to right on waist-level view screens, leaving it completely upside