A rangefinder is a focus mechanism that allows the user to calculate the distance of a subject through the convergence of two images. Cameras that use this mechanism are usually referred to as ‘rangefinders’.
Rangefinder cameras were very popular in the 1950s, 60s and 70s. Single Lens ReflexA Single Lens Reflex has a moveable mirror behind the lens, that reflects an image through a five-sided prism (pentaprism) or pair of mirrors, onto a glass screen (the viewfinder). This means the photographer sees exactly the same image that will be exposed. More (SLRsA single-lens reflex camera (SLR) is a camera that typically uses a mirror and prism system (hence "reflex" from the mirror's reflection) that permits the photographer to view through the lens and see exactly what will be captured. With twin lens reflex and rangefinder cameras, the viewed image could be significantly different from the final image. When the shutter button is pressed on most SLRs, the mirror flips out of the light path, allowing light to pass through to the film. Other camera typoes include DSLR, Rangefinder and Compact. More) and compact cameras largely replaced them in the 70s, 80s and 90s. What is not always appreciated is that rangefinders offer several tangible benefits over SLRsA single-lens reflex camera (SLR) is a camera that typically uses a mirror and prism system (hence "reflex" from the mirror's reflection) that permits the photographer to view through the lens and see exactly what will be captured. With twin lens reflex and rangefinder cameras, the viewed image could be significantly different from the final image. When the shutter button is pressed on most SLRs, the mirror flips out of the light path, allowing light to pass through to the film. Other camera typoes include DSLR, Rangefinder and Compact. More, not least in image quality. Indeed, many photographers would rate the Leica M Digital Rangefinder as one of the best cameras available today.