Re: [Leica] Flange measurements

[lea <lea@whinydogpress.com>]

Ma'am,

Yes, shooting with it is the best thing to do.

Cheers,
Lea (who is a member of LUG but NOT a member of the male persuasion)

"Dante A. Stella" wrote:

> Gentlemen:
>
> Interestingly, when I was supposed to be  getting ready for another day
> of work, I called Konica in New Jersey to grill them about flange
> distances.  After some audible page flipping, I was presented with the
> same 28.00 +/- 0.03mm figure Erwin got.  I also got some interesting
> tidbits regarding repairs:
>
>     1.    Konica USA expects any errors with Leica lenses to manifest
> themselves in the rangefinder, not in actual focus.  This is "by the
> book."  Erwin seemed to say that the German facility thought it would be
> actual focus.  That is a distinction between "focus" and "focusing."
>
>     2.    Measurements are made using a special device supplied by
> Konica Japan (hmm...) and are made from all four corners to the film
> plane (not clear how that is defined).  It may be impossible to
> duplicate the 28.00 measurement with anything else.  Makes me want to
> send them my M3 for measurement on the same apparatus.
>
>     3.    The Hexar body has eight adjustment points (4 in the lens
> flange and 4 behind the film plane).  All eight have alignment thrust
> washers installed when the camera is shipped.  This is, per John Van
> Stelten, how LTM cameras addressed this issue.
>
>     4.    The adjustment planes can be aligned, by virtue of the washer
> sizes, down to 0.01mm.  They did not indicate whether they actually did
> this.  On the M, the adjustment is behind the shutter.
>
>     5.    Alignment of the film plane necessarily follows any change of
> the shutter.
>
>     6.    The RF mechanism is aligned for linearity from infinity to 1
> meter.  This is the minimum distance without creating parallax problems
> in RF adjustment, or so they say.
>
>     Then later today, someone sent me an email message indicating that
> he measured his Hexar (with something called a depth gauge) to be
> 0.008mm from 27.80mm.  Putting two and two together, I would then wonder
> if
>
>     1.    Konica's measuring device is somehow different; or
>
>     2.    That different people may be measuring different ways.  The
> Hexar has two film rails, in part because it has no sprocket wheel (it
> uses some kind of optical sensing to determine frame spacing).  The film
> travels between the outer rails.  The pressure plate rests on both the
> back of the film and the outer rails.  The outer rails are about a
> film-thickness difference from the other (inner, on which the film
> rests).  Film thickness is... 0.13mm (for TMX135).  28.00-0.13 (or more)
> = 27.87.  If that clearance between the rails is indeed 0.2mm (to
> account for thicker film)... you end up with the magic 27.80.
>
> If I recall (my M3 has film in it), it only has one set of film rails,
> what would be the inner.  I assume that this is where the 27.80mm is
> measured.
>
> Maybe it's better to just shoot pictures with it.
>
> Cheers
> Dante

- --
Lea Murphy
Whiny Dog Press
816-333-9111
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