Please explain a rangefinder camera...

[Scottes]

What makes a rangefinder a rangefinder?
How do you focus one of these things?


Possibly related...
I remember that my father owned a very old camera at one time. It might have been a Leica. I think it had a gizmo in the case that I seem to remember being some type of distance finding aparatus. OK, I remember playing with this gizmo and faintly associate it with that camera... It might have been a split prism thingee and you read the distance from it?? It's been a while...

[Avalonthas]

Well basically its a system that calculates based on Triangulation, which is used to measure the distance of one point based on 2 other points (left and right), and it is usually used with telescopes to measure distances in space but can also be extended to binoculars and cameras etc. I learned how to do triangulation in science but i forget the exact process. I know the older ones you had to do the math urself but im sure todays digital devices can calculate them on there own without showing any more info. I am not sure where you would find such a device (i doubt it attaches to the camera, it is prolly resembles something like binoculars) So you can prolly find it at a hunting store or maybe a camera/telescopic store.

[Belmondo]

No, I don't know how they work, but I do have a good recipe for a quiche.

Actually, a rangefinder camera has a second image in the viewfinder. When the object you are photographing is in focus, the two images will be superimposed and appear as one. Usually there is a second window on the front of the camera body for the focusing image which comes to the view finder through a system of mirrors, one of which is movable and isconnected to the focusing knob/button/dial/lever/johnson bar.

[Penguin_101_1]

Read this: http://www.fortunecity.com/marina/marine/569/rusrngfdrs/focusing.html#here

[Scottes]

That didn't help Penguin. I know about HF distance. Thanks for the thought though.


OK, so I get the idea of HOW the rangefinder doo-hickey works. Simple triangulation using super-imposed images.

Is this the same way the RF camera works? And how do you get that to the focusing of the lens? By using the scale on the lens, which seems highly inaccurate to me...

[Penguin_101_1]

Sorry, I bookmarked it and posted it thinking it talked about it. This is from the manual for my rangefinder:
FOCUSING

1. Sight through the Viewfinder and turn the Focusing Ring until the two images in the center
focusing area form one clear image.
2. Compose picture within the bright frame which, during focusing, in particular at short distances,
moves diagonally for automatic parallax correction.
http://www.yashica-guy.com/document/g-manual.html

[Scottes]

So the Focusing Ring also focuses the lens?

[Penguin_101_1]

And this:
Rangefinder Design. From the beginning of their appearance in cameras, rangefinders varied in design. While they all depended on bringing two images into coincidence, they used different optical designs and the images created differed. Split-field rangefinders create a view in which the top half is from one window and the bottom half from the other. The superimposed viewfinder produces a window within a window with the smaller rectangle or triangle being produced from one rangefinder window within a larger image from the other window. Focusing brings these images into coincidence.

While the drawing above would suggest that split-field and superimposed rangefinders would do the job equally well, the difference in engineering strategies necessary to implement the designs meant that they did not perform equally well. Magnification could be added to the split-field type rangefinder to make the image more visible and to sharpen the point of division between image halves. The exact position of the eye relative to the finder was critical, however, and the magnification used made them difficult to combine with viewfinders, which were usually minified. This design works well when focusing on images with distinct vertical elements; in a scene with mostly horizontal elements, the camera must be turned diagonally or vertically, disrupting whatever the user might have done to compose the picture in the viewfinder. Superimposed rangefinders seemed more intuitive to users and could be more easily integrated into viewfinder systems. Since either the larger or smaller window was colored to increase the contrast between the two, superimposed rangefinders were usually darker than their split-image counterparts.
http://www.prairienet.org/b-wallen/BN_Photo/RFPrin2.gif

Closed the window before I got the link, but it was on prairientet.org

[Penguin_101_1]

So the Focusing Ring also focuses the lens?

The focusing ring should be on the lens and it will focus the diamand in the rangefinder (viewfinder) and the lens.

[Scottes]

Cool. Thanks folks!

[Moppie]

Wow, Iv wanting to know how they worked for some time, but never for round to finding out.

Even when you ask a Q. Scottes everyone learns something, and it must be great for your post count. ;)