Re: [Leica] infinity focussing

["Julian Thomas" <mimesis@btinternet.com>]

Thanks to all who helped with this. My M6 is still under passport so I'll
throw it back to leica! (gently of course).

Julian

- ----- Original Message -----
From: "John Collier" <jbcollier@home.com>
To: <leica-users@mejac.palo-alto.ca.us>
Sent: Tuesday, April 25, 2000 1:58 AM
Subject: Re: [Leica] infinity focussing


> Usually the camera rangefinder needs adjusting but occasionally  the lens
is
> the problem. Have you tried the camera with other lenses? Here is a
message
> from the archives that explains the rangefinder adjustment if you feel
> handy:
>
> ----------
> From: Javier Perez <japho@cunyvm.cuny.edu>
> Reply-To: leica-users@mejac.palo-alto.ca.us
> Date: Mon, 27 Mar 2000 05:28:39 -0500
> To: leica-users@mejac.palo-alto.ca.us
> Subject: Re: [Leica] Leica Users digest V16 #75
>
> > Date: Sun, 26 Mar 2000 20:50:24 -0800
> > From: "Stephen Attaway" <attaway@slip.net>
> > Subject: [Leica] Horizontal Rangefinder Adjustment on M - what is the
secret?
> >
> > Esteemed LUGers:
> > The rangefinder on my M4P is off by a tiny bit at infinity, just enough
to
> > notice two lines where only one should be when focused on a distant
> > flagpole. I sent it in to Gasser's, who checked it and said it looked
ok.
> > Yet it still bugs me. Does this small error make any practical
difference?
> > Its pretty clear to me the adjustment is not made in the same way as a
IIIf
> > or a Canon7, as there is no adjustment screw where I expected to find
one.
> > I looked up rangefinder alignment in the archives, and found that the
screw
> > that was not there would have adjusted vertical alignment, had I owned
an
> > M4, M3 or M2. So I am glad I did not find it, in a way. Someone, I
believe
> > it was Mark Small, stated that horizontal alignment was "user adjustable
and
> > required a special tool". It looks like there is an arm to adjust an
> > eccentric on the pivot for the rangefinder cam.
> > Can anyone tell me the procedure for adjusting horizontal alignment on
the M
> > and what special tool is needed? Of course if the procedure is to ignore
> > small errors until a CLA, I can live with that.
> > Kind regards,
> > Stephen Attaway
>
> Howdy
>
> Here's what works for me. I don't know how Leitz does it.
>
> First ascertain that both images are focused with respect to each other.
> This is done by focusing slightlty ahead or behind a vertical object and
> then
> shifting
> the position of your eye left right up and down within the eyepiece. The
two
> images
> should not
> move with respect to each other. If they do, turn the threaded lens in or
> out until
> the images
> are stabilized. I have an M6 came right from of the factory with this
> problem as
> well as off
> parallel curtains!
>
> There are 2 adjustments that affect horizontal position. The first being
an
> eccentric on the
> rangefinder pivot which regulates cantilever length. A second ecentric is
on
> the
> rangefinder wheel itself and controls cantilever angle with respect to the
> lens
> focusing position. Both are accessible once the lens is removed. The trick
> is to get
>
> the right angle at infinity by adjusting the wheel eccentric until the
> images
> coincide
> exactly and then focus on a closer object and check focus there using
either
> a spare
>
> focusing screen or a reference camera. Adjust close focus by turning the
> cantilever
> eccentric.
> Now refocus on infinity and pray that the alignment is still perfect. If
> it's not
> repeat the process zeroing in until both ranges are ok or until u go nuts.
>
> There are other factors which can affect horizontal alignment. One
> is the position of the rangefinder itself. It can be moved front or back
> ever so
> slightly
> by loosening the 2 screws under the rewind end of the chassis as well as
the
> one
> right
> behind and under the rangefinder wheel. The position of all glass will
also
> affect
> the focus.
> The angled magnifier can be pushed in or out to change both horizontal and
> vertical
> image but should not be touched unless the camera has been knocked real
> hard. The
> front
> element can be shifted left and right but it's also set at the factory and
> shouldn't
> be touched.
> Ditto for the prism It's major surgery and can keep u busy all day.
>
> Finally, if the infinity misalignment is within the depth of field on a
long
> fast
> lens at max
> aperture and close/mid focus is ok, you're better off not touching it.
> Unless the
> camera was
> dropped, this was the point where the Leitz tech, who was using
> sophisticated
> alignment tools, said ok. It's good to go. It's doubtful that any of can
> improve
> upon that.
>
> BTW: I've run in to some cameras that just won't align perfectly no matter
> how much
> you fiddle with them possibly because the cam was malformed or is badly
worn
> but
> they are still within specs
>
> *** Warning make sure that you support the rangfinder cantilever when
> adjusting the
> wheel
>        or better yet remove the cantilever entirely it to perform the
> wheeladjustment.
>        Excessive angular loading will kill the rangefinder bearinng and/or
> cantilever instantly!
>
> Lots a luck
> Javier
>
>
>
>