[Leica] Accuratization*/Perfectionist/ Addendum / Why Not?

[Leikon35 <Leikon35@aol.com>]

   From the private mail that I have received, it seems that I have failed to
   make myself clear & am adding this bit of trivia.
- -----------------------------

   The early Leicas had fixed lenses (non-interchangable) and had to be
   matched to the individual bodies.  In 1931/32 the bodies were all made
   to  (I forget exactly but think a 28.xxxxmm) standard &  a little "o" was
   added to the bodies lens flange & also to the now standardized lenses.

   Now the body focal plane to lens flange distance were all the same but
   it was too costly to produce all lenses to that same tolerance, so each
   lens was matched to a tube (mount) that corresponded with its true focal
   length and any errors were compensated for by the depth of focus of the
   majority of the lenses max. speed of f:3.5 .  

   It was only the perfectionist (like the driver that has his engine blue
printed)
   and dyno-tuned) that insisted on 100% accuracy. As a subject that already
   has been covered on the LUG --- 100% superimposition of the 2 rangefinder
   images is not really neccessary but since it is easy to obtain "Why Not"?

   When we go into the realm of the Summilux & Noctilux lenses,  with close
   distance DOF of only inches --- then as Leica recommends: match the lens
   to the camera if you want accurarcy in inches with a rangefinder. By the
way,
   for those of you that didn't know - An "aerial image" is one formed without
the
   use of a ground glass (just in the air like a telescope).

    MMoss
  ========================================================  
 In a message dated 98-04-15 17:53:02 EDT, Marvin wrote:
<< 
  Those of you that are seriously into fine tuning guns will know immediately
  what I am talking about but for the rest of you Leicaphiles, bare with me.
 
  All early Leica cameras had problems in matching a lens to its body, since
  the actual focal lengths varied ie (+ or - 1/10mm) and the bottom shells,
not
  being die cast also varied.  The solution to this, in the late '20s & early
 '30s
  was to have a PEEP HOLE built into the back of the camera where a loupe
  was attached ( quite similar to what Harold has just done) but since they
  were focusing on the aerial image rather than a ground glass, it was more
  accurate. After adjustments by adding shims ( .001/mm ) to the lens flange
  the peep hole was plugged and the pressure plate revolved to make it light
  tight.  My exact figures might be off a tad but believe me - they were thin.
 
  When I worked professionally with Leicas back in the "50s to '70s, serious
  35mm still photographers sent their Leica to Mel Pierce to have the lenses
  matched to the bodies.  Although this really wasnt necessary after the die-
  cast bodies were made to closer tolerances, the lenses still had a variance
  in focal lengths.  You can still see the # 0-9 stamped on many lenses - but
  that is another story already fully covered on the LUG last year.
 
  Even today, you will read about recommendations to have your high -speed
  lenses ( particularily the Noctilux)  matched to your individual camera. 
 
  I think it was either Browning or Winchester that got the idea of speeding
up
  production by making closer tolerance parts that could then be interchanged.
  In my days of racing Porsches, an overhaul after each race was not unusual
  and the pistons & cylinders were graded in groups by 1/10,000" differences;
  the pluses balancing the minuses.
 
  Marvin  Moss