Rangefinder camera

A rangefinder camera is one with a double viewfinder, allowing the photographer to judge the focusing distance. The rangefinder shows a double image, and lining up the two images of the object to be focused on more or less accurately gauges its distance. Older cameras may display the focusing distance and require the photographer to transfer the value to the lens focusing ring; most recent designs are coupled rangefinders - that is, the focus is adjusted both in the rangefinder and in the objective lens by the same control.

The most famous rangefinder cameras are the Leica M-series. The latest of these is the M7, which is the first of the series to feature automatic exposure. Other current models include the Contax G1 and G2, the Konica RF, the Voigtländer Bessa R2, and the Hasselblad Xpan. Leica-derived cameras from the former Soviet Union, such as Zorki and Fed, are fairly common in the used market. These all take 35mm film; there are also medium-format rangefinders like the Mamiya 7, the Bronica RF645 and the Fuji G-series.

Rangefinder cameras are less commonly used than single-lens reflex models. SLRs are usually more technically advanced, with more system options, and have the advantage that the image is seen through the same lens through which it is photographed. Since the user looks through a viewfinder some distance from the lens and sees an image which is slightly different from the image which will be recorded on the film framing becomes inaccurate at close range (Parallax problem). However, more advanced rangefinder cameras project a frameline into the viewfinder which corrects parallax error at all but very close imaging distances. For close-up photography, the rangefinder camera is inappropriate, as the image recorded may be significantly different from what the viewer sees.

Rangefinders do have several advantages over SLRs in certain applications. Since there is no moving mirror, as used in SLRs, the shutter response is very fast and quiet and the camera's body is slim and unobtrusive. The lack of a mirror also allows lenses to project deep into the camera body, and so higher quality wide-angle lenses are possible. (The Voigtländer 12mm lens is the widest-angle non-fisheye lens in general production.) The rangefinder focusing system is more accurate with standard and wide-angle lenses (whereas an SLR is more accurate with telephotos). The rangefinder focusing system is also faster and more accurate than manual focusing an SLR in low-light conditions. Since rangefinder cameras are simpler, they tend to be more durable - while some Leicas are collectors' items which are treasured and protected from the slightest scratch, they are nonetheless capable of withstanding considerable abuse and have been widely used by photojournalists. These qualities make rangefinders ideal for action-grabbing candid shots and street photography.