Re: [Leica] focus at infinity

[thibault collin <tc-lnc@u-picardie.fr>]

Thanks Jim,

>Speaking of focus at infinity, which do you trust?  The rangefinder or the
>lens' infinity stop? 
Actually, both positions are identical on this lens, i.e. the lens infinity
stop perfectly matches the infinity symbol. Will I have to get the lens
serviced?

Thanks once more.

Thib.


 You'll notice that when you set any M lens at the
>infinity stop, the coincident images in the rangefinder patch are just ever
>so slightly off.  You just barely back the lens off the infinity stop and
>the coincident images line up perfectly.  I'm talking about a difference
>equivalent to the width  of a hash mark on the lens barrel.  All my
>rangefinders do this, including both M6s and the Mamiya 7 and the dealers
>for both cameras tell me it's normal and done to allow for
>expansion/contraction of materials in varying temps.  Indeed, on hot days,
>this effect seems to be less pronounced than on cold days...
>
>I assume the infinity stop is "true" infinity, right?  This probably doesn't
>matter since I can never tell the difference between frames taken at the
>infinity stop or backed off to make the rangfinder line up, but would like
>to hear the group's comments.
>
>--Jim Laurel
>
>