SLR means Single Lens Reflex camera, which uses mirror and prism system to focus the image directly in the view path of the lens by the photographer. In old cameras, there are two view paths to target the image. One path is through the lens of the film and another path is the viewfinder which is positioned above or to the side of the lens. The viewfinder and optical path of the lens both have its own individual paths. This does not cause any troubles and complications in the image output which are captured at short and moderate distances. For longshots, it will cause a problem in the image due to a thing called parallax. Viewfinder’s aim is different from that of the image captured through the lens. To solve this complication, both the paths should be intersected to get straight and perfect view path through the lens of the camera. When the shutter is released, light enters through the lens and the image is captured. The light which comes from both the horizontal and vertical directions is inverted, and it is reflected upward by the reflex mirror and finally, the image is aligned with the viewfinder. For taking photographs at long distances, SLR camera delivers high-quality images with better accuracy in pixels.