[Leica] Summilux 50mm 1.4 ASPH

[hoppyman at bigpond.net.au (G Hopkinson)]

Jeff, the other lens reported by Leica to exhibit zero focus shift on the M8 
is the f2 75 asph,  which shares the same exotic design
with floating element as the 50 asph.
The focus shift issue is discussed quite a bit in the Leica User Forum.
Two lenses that people have mentioned as having the problem most are the 
Nocti and the 1.4 35 asph.
Focus shift means that the sharpest plane moves when the aperture setting is 
altered. This is not unique to Leica lenses. It is most
obvious with fast lenses one or two stops down from wide open (which is 
where Leica lenses love to live). At smaller apertures the
effect is masked by DOF. The effect is much more apparent with digital 
capture and examination of images at high magnification.

LFI has had a recent article on it. 

Cheers
Hoppy

-----Original Message-----
Subject: Re: [Leica] Summilux 50mm 1.4 ASPH

2007-09-13-17:39:23 G Hopkinson:
> they are one of the two lenses that Leica reports
> has zero focus shift on the M8.

I'd love more information on this -- What's the other "good" lens?
What's the precise definition of/cause of/degree of this shift in other
lenses?  Is there a deeper discussion of this somewhere?

 -Jeff, whose 50mm ASPH has been stunningly good but whose Noct hasn't
        gotten back from Germany yet

_______________________________________________
Leica Users Group.
See http://leica-users.org/mailman/listinfo/lug for more information