RangeFinders

A rangefinder camera is a camera fitted with a rangefinder: a range-finding focusing mechanism allowing the photographer to measure the subject distance and take photographs that are in sharp focus. Most varieties of rangefinder show two images of the same subject, one of which moves when a calibrated wheel is turned; when the two images coincide and fuse into one, the distance can be read off the wheel. More modern designs have rangefinders coupled to the focusing mechanism, so that the lens is focused correctly when the rangefinder images fuse.

The viewfinder of a rangefinder camera is necessarily offset from the taking lens, so that the image shown is not exactly what will be recorded on the film; this parallax error is negligible at large subject distances, but increases as the distance decreases. More advanced rangefinder cameras project into the viewfinder a brightline frame that moves as the lens is focused, correcting parallax error down to the minimum distance at which the rangefinder functions. The angle of view of a given lens also changes with distance, and the brightline frames in the finders of a few cameras automatically adjust for this as well. For extreme close-up photography, the rangefinder camera is awkward to use, as the viewfinder no longer points at the subject.

In contrast, the viewfinder pathway of an SLR transmits an image directly “through the lens”. This eliminates parallax errors at any subject distance, thus allowing for macro photography. It also removes the need to have separate viewfinders for different lens focal lengths. In particular, this allows for extreme telephoto lenses which would otherwise be very hard to focus and compose with a rangefinder. Furthermore, the through-the-lens view allows the viewfinder to directly display the depth of field for a given aperture, which is not possible with a rangefinder design. To compensate for this, rangefinder users often use zone focusing, which is especially applicable to the rapid-fire approach to street photography.

The rangefinder design does not lend itself to zoom lenses, which have a constantly-variable field of view. Very few lenses, such as the Konica M-Hexanon Dual or Leica Tri-Elmar, let the user select among two or three focal lengths; the viewfinder must be designed to work with all focal lengths of any lens used. On a technical level, the rangefinder may become misaligned, leading to incorrect focusing, a problem absent from SLRs.

Nonetheless rangefinder cameras have advantages over SLRs for certain applications. Since there is no moving mirror, as used in SLRs, there is no momentary blackout of the subject being photographed. The camera is therefore often quieter, particularly with leaf shutters, and usually smaller and less obtrusive. These qualities make rangefinders more attractive for theater photography, some portrait photography, action-grabbing candid shots and street photography, and any demanding application where portability matters. The lack of a mirror allows the rear element of lenses to project deep into the camera body, making high-quality wide-angle lenses easier to design.

Rangefinder users also sometimes talk of a “stream of consciousness” approach to shooting. The key to this is that rangefinder viewfinders usually have a greater field of view than the lens in use, with the photographer being able to see what is going on outside of the framelines and therefore better anticipate action.

If filters that absorb much light or change the colour of the image are used, it is difficult to compose, view, and focus on an SLR, but the image through a rangefinder viewfinder is unaffected. On the other hand some filters, such as graduated filters and polarizers, are best used with SLRs as the effects they create need to be viewed directly.

Chris Weeks who is a well known street photographer, and whose work is regularly published in vogue, rolling stones, OK! and other big magazines, is a big fan of rangefinders. He has a wide range of amazing photos shot with rangefinder cameras. Below are a few of my personal favorites

~ Source: Wikipedia.org