[Leica] Production figures M6 .85/aspheric lenses/best lenses

[Erwin Puts <imxputs@knoware.nl>]

Eric stated that Leica sold 'only' 4000 HM's over the total production
period. In a full year Leica produces about 10500 M bodies. The M6HM has
been in production for less than a year. That would amount to almost 50% of
total yearly production. In my view a very successful model. The latest
shareholder report stated a small reduction in M sales. Would that
reduction be higher had the M .85 not be offered?  I think so.

Pascal Asked:
Aspheric lenses have very small (a few microns) deviations from a true
spherical shape. Leica now uses two different methods of getting this
aspherical shape. The well known 'blank pressing" that uses a ceramic mold
to press the hot and slightly soft lens element 'into shape'. Only a few
types of glass (all produced in japan) are able to withstand this handling
and still to give the prescribed optical performance. Zeiss by the way uses
the same glass. One limitation to designers then is the small selection of
glass types, the other being that this method works fine for lens elements
with a diamter below 30 or 20mm.
The new method, now increasingly Leica's favorite, uses a CNC controlled
polishing machine. No choice limitations and no radius limitations. As I
stated earlier, while aspherics can improve performance in a number of lens
types, they are also used for other purposes in the design and production
process. Again let us not be overzealous. To assume that only an ASPH tag
will deliver the utmost in performance is a bridge too far. Leica are
leading in ASPH designs for sure. Every lens should be evaluated on its
performance whatever the tag attached to it.

Francesco asked about the best lenses:
Leica lenses do differ between the M and R system and within both systems.
These differences are quite real and provable. One has to ask oneself if
the kind of picture taking and the mastery of technique can support the
exploitation of these fine differences. To give some not wholly
unrealistical statistics. The best leica lenses differ by about 5 to 10%. A
superb lens having 100%, an outstanding one 95%  and an excellent one 90%.
The photographers technique can influence this performance in such a way
that the overall performance of the superb lens approaches an overall
performance figure of 50 (halfway the maximum). But now the other two types
of lenses will also get that level of 50. The potential differences are on
such high a level that the photographer will never experience them given
his technique or subject matter or shooting preferences. Using f/8.0,
handheld or on tripod and using (fill-in)flash will almost nullify any
performance difference.

Erwin