Archived posting to the Leica Users Group, 1999/11/24

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Subject: Re: [Leica] Leica Users digest V13 #55
From: "R. Carter" <carter@andromeda.rutgers.edu>
Date: Wed, 24 Nov 1999 08:51:46 -0500

Skip Williams wrote on Tuesday. Nov. 23:


> I just wanted to let the group know that I had a real nice experience at
> Leica USA in NJ.today.
> 
> My M6 Titanium was not focusing at infinity according to the rangefinder,
> although the lens was going all the way to the infinity mark.  So I took it
> in at 9:30am and a nice fellow asked me a few careful questions like: "Is
> the lens firmly mounted?"  "Does the lens go to infinity?".  After I
> explained the issue, he took the camera with its 35/2 in the back and
> returned about 5 minutes later.    "Is it fixed?" I asked.   "Yes, the
> rangefinder just needed a little adjustment." he replied.
> 
> All in all, a very pleasant experience.
> 
> I also enjoyed looking at all the historical cameras in the glass case,
> like the M1 with the Leicavit MP and the Uhr-Leica reproduction.
> 
> The nagging question is: How easy do M6 rangefinders get out of
> adjustment?   I know the tech turned one or two of those little screws
> inside the lens mount on the rangefinder mechanism, but I don't know which
> one(s).  Any clues as to DIY adjustments?  (Although with Leica USA just
> 45min from my house, it isn't a big deal.)
> 
> Skip
> 
> - -----------------------------------------------
> Skip Williams
> Westfield, NJ
> skipwilliams@pobox.com
> - -----------------------------------------------

I believe M6 rfdrs (like all M rfdrs) sometimes get out of
whack by being whacked, in which case I always go to a good
repairman.  Sometimes, however, the appearance of a considerable
maladjustment of the infinity stop can be given by tolerance
stacking, especially if you are using  an elderly or
non-Leica LTM, perhaps with a non-Leica bayonet
adapter. So, if you get infinity problem, the first step
should be to try some of your other lenses.  If you only
have a problem with lenses you do not use much, don't use
them much.  If two important lenses don't match, adjust for
the longer one.  Tip:  When checking, check on something
very far away.  A tall water tower  2-3 miles away is good.
The moon is better.

With the lens off, look at the wheel (about 3/8 in.) on
the end of the focus cam (the thing you can wiggle with
your fingertip to move the focus spot from side to side
as you look through the rfdr).  You will see thin screw
slot in the center of the wheel. Slightly rotating that
screw slot in the center of the cam wheel adjusts 
coincidence at infinity.  To move it, you need two tools you
can make.  Get a couple of screwdrivers with fine blades
about 2/5 in. wide and (with a fine file) dress the
blades until thin enough to fit in the screw slot
in the cam.  Now you have to take each of the screwdrivers
and bend the tips so that each is at a 90 degree angle to
the shaft. You need two because one screwdriver blade
(after bending) has to be positioned to engage the cam
screw slot when it is positioned parallel to the 
film plane and the other has to be able to fit in the
slot when it points perpendicular to the film plane.

For bending, you need a small gas torch or access to 
a burner of a gas stove, a small vise (or heavy pair of
pliers) and a half-cup of motor oil.  Heat the part of
the screwdriver shaft you want to bend until it is 
reddish yellow in color, then bend it in the vise.
After it is bent, quench it in the oil to keep the
temper and scrape the scale off the finished tool.

When the tools are done, adjust the cam screw slowly
and carefully, checking frequently by inserting the
lens you are matching and testing against your
infinity target. Done with caution, this works fine.

In my experience, vertical maladjustment usually
is the result of dropping the camera.
Vertical adjustment of the rangefinder spot in 
M2, M3 and M4 bodies is done by removing the capscrew
on the front of the camera just at to the left of the 
frameline illuminating window and inserting a jewelers
screwdriver to tweak the adjustment screw inside.
This is chancy. Better to take it to a pro who can
remove the top cover and use a factory jig to hold
the rfdr parts in place.  Vertical coincidence on
the M4-2, M4-P and M6 cannot be adjusted by mere
mortals like me.  Likewise, I know nothing
of the M5 rfdr.

BTW, is Leica USA, Northvale the same address as what used to be
E. Leitz, Rockleigh? I.e. would the directions be the same?

[My file from Rockleigh days says: (1) Tpke to 80 (GW), (2) To
Palisades Pkwy (3) N. to Exit 5 So. [303] (4) 3 lites then
at 4th lite (5) take L. onto Paris Ave. (6) Cross RR track then
(7) 4 blocks, then (8) R. onto Veterans Dr., then (9) 2 blocks
and then (10) L. onto LeGrand Ave. (11) 1/3 block, then
(12) LH side, 2d door in parking lot.]  Does that sound familiar?
If not, can you please give me the right directions?
- -- 
                                             _RAC

Robert A. Carter KB2NTV carter@newark.rutgers.edu
15 Washington St. Newark NJ 07102 +1.973.353.5216