DSLR

Digital single-lens reflex cameras (also named digital SLR or DSLR) are digital cameras combining the parts of a single-lens reflex camera (SLR) and a digital camera back, replacing the photographic film. The reflex design scheme is the primary difference between a DSLR and other digital cameras. In the reflex design scheme, light travels through a single lens and a mirror is used to reflect a portion of that light through the view finder - hence the name Single Lens Reflex. The image that is seen through the view finder is also the image that is captured by the camera's sensor.
Like SLRs DSLRs typically use interchangeable lenses (1) with a proprietary lens mount. A movable mechanical mirror system(2) is switched down (exact 45-degree angle) to direct light from the lens over a matte focusing screen (5) via a condenser lens(6) and a pentaprism/pentamirror (7) to an optical viewfinder eyepiece (8). Most^{[citation needed]} of the entry level DSLRs use apentamirror instead of the traditional pentaprism. The pentamirror design is composed mostly of plastic^{[citation needed]} and is lighter and cheaper to produce — however, the image in the viewfinder is usually darker.