DSLR (Digital Single Lens Reflection) is camera that uses a complex mechanical mirror system to redirect light that enters through the lens. DSLR cameras are often more sensitive and versatile and produce a better quality image. DSLR so popular, and the right choice for you. A digital DSLR camera works by using a reflective mirror (or prism) that reflects light into the optical viewfinder, allowing the photographer to capture the image he wants in front of him. Light passes through the lens and is reflected back to the mirror or prism inside the camera body.