[Leica] BESSA R3A or M7

[billgem at hotmail.com (Bill Marshall)]

Sorry about any confusion I may have created in describing Cosina's 
manufacturing practices employed with its Voigtlander lens line as evaluated 
by the esteemed Mr. Puts. Perhaps I should have used the term "greater range 
of tolerances."

Jeffrey, Zeiss did talk about focus shift in its lead up to Photokina & it 
is again mentioned on it Zeiss Ikon website. Specifically, it says that its 
lenses are designed to "minimize focus shift." Since I have no idea what 
they did to achieve this, I find it to be an interesting question regarding 
whether this would also be accomplished if the lens is on a body other than 
the ZI. Since they specifically state that it is an issue of lens design, I 
assume that it would. Also since the original Dagor design back in the 1890s 
had significant problems with focus shift, I assume that some lens designs 
are prone to greater shifts of optimal focus point with aperture changes 
than others.

Zeiss emphasizes the greater precision of focusing that they have achieved 
with this new camera system by virtue of its long effective base length & 
this minimization of focus shift - an issue highlighted by the indubitable 
Mr. Puts in his review of the Noctilux. If Zeiss has accomplished this, it 
will be a significant benefit especially for photographers who work at or 
close to full aperture on fast lenses.

In what is, I assume, an unrelated comment of marketing promotion, Zeiss 
says that its "bright & sharp rangefinder field . . . does not shift or 
wander when focusing." I only mention it here because it is another mention 
of "shift" in relation to focus.

Cheers,
Bill