Rangefinder camera
"Rangefinder" refers to the type of optics used in a camera. Popular in the '30s, '40s and 50s', rangefinder cameras were essentially replaced by today's single-lens reflex (SLR) cameras.
Origin of the rangefinder
Rangefinder camera
The rangefinder camera was introduced in 1932. It was largely responsible for making photography popular among non-professionals since earlier cameras where much larger, significantly heavier and used optic systems that projected inversed images prior to capture.
Two images become one
Today's SLR cameras offer 'through the lens' or TTL image viewing. Rangefinders don't have TTL image viewing. They use a different type of viewing system.
On a rangefinder, you look at the image through the viewfinder, but the image comes into the camera from a different window. The result is that you see two images: one slightly imposed on the other. The camera is in focus when you turn a focus ring around the lens until two images line up.
The focus from a rangefinder camera is incredibly precise, which is why it remains a favorite among professional photographers---even those who shoot film or digital SLR 35mm or medium format cameras.
Photocomposition
Since the perspective of shooting with a rangefinder is different than from a SLR or other TTL camera, it may take some time to adjust your photocomposition technique. It may require more skill---or at least a finely honed "eye"---to properly frame an image with a rangefinder.
Benefits
The difference between a good picture and a great picture is timing. Even a millisecond of shutter lag can cause you to miss a great shot. Rangefinders don't use the same type of mirror optics as SLR cameras do. With no moving mirror, there's no shutter lag.
Rangefinders can offer a higher quality photograph. Without the mirror, the lens can get closer to the camera's image plane. The image plane is where the magic of creating a photograph happens. And because there's no moving mirror, there's less likelihood of blur created by the mirror movement at slower shutter speeds.
Rangefinder cameras are smaller and lighter. Since they have less glass, the cameras weigh less than SLRs. The cameras perform better with smaller lenses, which also means less weight.
Disadvantages
With rangefinder cameras, what you see in the viewfinder and what you capture through the lens are two different things.
Bigger lenses may block or interfere with the viewfinder. This means that you won't want to shoot with most of the larger telephoto and fisheye lenses. Zoom lenses don't work well on rangefinder cameras either.
Range finders aren't designed for macro or super close-up images. They shoot best at medium and long distances.
Tags: image plane, image viewing, mirror there, moving mirror, moving mirror there, other camera