What is SLR photography?

Digital SLR camera is a kind of digital camera which uses the new technology of single lens reflection. The abbreviation of this new technology is SLR (single lens reflex). This technology is to install a pentaprism above the ground glass in the camera and place it in front of the film plane at an angle of 45. This prism reflects the real image light many times to change the optical path and send the image to the eyepiece, so that the image seen in the observation window is always the same as that on the film, and the observation range is basically the same as the actual shooting range. The unique design of this prism enables the photographer to directly observe the image passing through the lens from the viewfinder.