[Leica] M6 rangefinder/viewfinder

[Frank Dernie <FrankDernie@compuserve.com>]

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.

And Doug Richardson replied:-

>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.



I am the proud owner of two cutaway Leicas, one a very early DS M3, the
other a M6. The viewfinder/rangefinder design of the two is COMPLETELY
different. The only thing they have in common is the external position of
the windows! The rangefinder, prisms and frameline masks are different and
in different places. I was astonished by this.
I have read that the M2 was a cheapened M3 and the savings were made in the
viewfinder/ rangefinder. I do not know whether the saving is because the
design was simplified or because the precision could be made lower due to
the reduced magnification. A M3 replacement viewfinder/ rangefinder is
still about 50% more expensive to replace than the others. I do not know if
a M6 viewfinder/ rangefinder would be fitted to a M2 if it needed replacing
or whether all .72 viewfinder/ rangefinders are cheaper than 0.91s.

I do not know if the design change took place between the M3 and M2 or some
time later. Since everybody likes the M2 I imagine that, if the
deterioration in viewfinder/ rangefinder quality is due to the design
differences, it is most likely to have taken place between M5 and M4-2.

Surely Walt knows if he has serviced all the models?
Cheers Frank