[Leica] M6 rangefinder/viewfinder

["Doug Richardson" <doug@meditor.demon.co.uk>]

Commenting on the quality of the M6 finder, Bill Rosauer wrote:

>The design of the rangefinder/viewfinder has not changed per se,
although the
design has been simplified and has fewer parts than the original M3's.

The diagrams of the optical path shown in Leica literature for the
early Ms and for the M6 show a different layout. On the original
finder the optical path of the rangefinder was based on 90 degree
prisms, so ran either from back to front or from side to side. On the
M6, the optical path of the rangefinder runs from just behind the
eyepiece, forward and across the body to small rangefinder window.

On the original design the finder frames were mounted behind and
parallel to the frame-illumination window. On the M6, they are mounted
at an angle to the frame-illumination window so as to be at 90 degrees
to the new optical path of the rangefinder. A small curved mirror
located behind the frame-illumination window redirects the incoming
light onto the frames. I suspect that this indirect illumination is
the reason why the right or left hand vertical sides of the finder
frames "dim out" if the eye is not directly centred on the eyepiece.

I bought an M6 because both of my M2s were starting to show symptoms
of "vulcanite disease", and find the M6 finder a great disappointment
after that of the M2.  As a result I've abandoned plans to build up a
complete M outfit by adding 90 and 135mm lenses. I'll keep using the
SL2 as my main system camera and use the M6 for use what that camera
does best - fast work (particularly in lower light conditions) with
the 35mm and 50mm lenses. The M6 will also be my "fun" camera - I
enjoy taking photos with a rangefinder camera.

Regards,

Doug Richardson