[Leica] Noctilux DOF Film vs M8

[amr3 at uwm.edu (amr3@uwm.edu)]

 "Geoff Hopkinson" <hoppyman@bigpond.net.au> wrote:

> LFI reports Leica's position as that the focus shift when stopping down a
> little has always been there (with fast lenses) but is more detectable with
> the M8 due to several factors. Purportedly, only the 50 asph and the 75AA
> that shares its design are immune.
(snip)
> I have heard about the infinity point adjusting in the M8 body, but the
> shimming is new to me.
(snip)
> No question but that I am noticing missing focus with the 50 asph using it
> close-up stopped down to f4 or so.
............................................................................................................................................
This might not be relevant to the current discussion, but perhaps 
interesting in
a historical sense:

In an article on the Leica system by Arthur Kramer in the Oct/Nov 1961 issue 
of
Camera 35, from his Re-Evaluation series, he reported on the care Leitz took 
to
obtain consistent focus.

An excerpt: "These variations in focal length, if they are to provide 
critical
sharpness, must be compensated.  Here's the astounding way in which Leitz
accomplishes this.  For every Leica lens there is a SERIES of focusing mounts
which contains the proper cam and thread pitch to provide accurate tacking.  
As
many as 18 mounts are available for certain lenses.  Focal length variations
which fall outside or between the values for which mounts are available are
rejected.  In this way, tolerances come closer to approaching zero than in
equipment where this is not done.  This is probably the only way in which a
rangefinder camera can truly have 'interchangeable' lenses which will be 
highly
accurate to a given back focus and coupling system"

I wonder if this is still the norm with Leica lenses?

Alan

Alan Magayne-Roshak, Senior Photographer
University Information Technology Services
University of Wisconsin-Milwaukee
amr3@uwm.edu
http://gallery.leica-users.org/v/Alan+Magayne-Roshak/