Re: [OM] Rangefinder?

[Winsor Crosby]

>  > Could someone explain the Rangefinder philosophy/technique in simple
> >  phrases ;-)
> >  I know what they look like and so, but what's good/bad/special with them?
> >
> >  Thanks
> >  Henrik Dahl
> From my understanding, the rangefinder basically has a few prisms in it; you
> look out the viewfinder window, and it has a picture of the image you want
> to take a picture of, and then another image though the lens as well.  When
> the two come together, then your picture is in focus.  The problem is,
> unlike an SLR, you always get the same view, it's not in correct perspective
> with respect to the mm of the lens like an SLR.  In an SLR, basically
> WYSIWYG.  In a Rangefinder, it's not true.
>
> The advantages are; like a Leica M6 for example, because there is no mirror
> flap, it's very steady, it's also very quiet.  Also, due to the lack of a
> mirror, it's very compact in depth, and overall size.
>
> albert
Part of the accuracy of a rangefinder is dependent on the length of 
the baseline which is the distance between the two little windows on 
the front of the camera.  The same principle is used in the split 
image focus aid in an SLR screen.  In the SLR the base is limited by 
the diameter of the lens, but it is also dependent on the 
magnification of the lens. The result is that while focus is usually 
very accurate with a rangefinder lenses up to about 100mm and not 
great after that, but SLR focus is strongest when the image is 
magnified by a telephoto lens and weakest with wide angles. 
Fortunately for the SLR its focus weaknesses at wide angles are saved 
by depth of field. The longest lens attached to a rangefinder is 
usually a 135mm on a Leica which has a very long rangefinder base and 
at one time they made a special 185 mm lens with rangefinder window 
magnifiers attached so you could focus it. Leica made also made a 
reflex adaptor complete with swinging mirror and prism housing to be 
used between the M cameras and long lenses. That was NOT quiet.
--
Winsor Crosby
Long Beach, California

< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >