Archived posting to the Leica Users Group, 2009/08/10

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Subject: [Leica] 24mm lens has incredible powers...
From: hopsternew at gmail.com (Geoff Hopkinson)
Date: Mon, 10 Aug 2009 18:28:52 +1000
References: <206027BF-A3F0-4C72-8367-95C03E19EFA9@frozenlight.eu> <7ac27f4f0908092357t7ce90617n7b937061e950b85b@mail.gmail.com> <36172e5a0908100127j3d71e4bco4419b593be7120e3@mail.gmail.com>

---------- Forwarded message ----------
From: Geoff Hopkinson <hopsternew at gmail.com>
Date: 2009/8/10
Subject: Re: [Leica] 24mm lens has incredible powers...
To: Leica Users Group lug at leica-users.org


Hi Nathan. I just tested mine for you against point light sources, the first
a couple of km away and the second a couple of hundred light years away. I
think we will take both as practical infinity. Mine has maybe a just
perceptible difference between the two.  I think only with Leica lenses
would you be expecting to feel any difference there! The star is exactly at
the limit of detectable travel with mine. I think no practical difference or
effect. Does yours stop exactly aligned with the infinity mark on the focus
ring when turned to the stop? Any tiny error may actually be in the marking
accuracy rather than any focus adjustment. Very likely within normal
tolerance anyway.

My opinion is that what you have described will cause zero practical effect.
Wide open set at infinity your Dof will stretch back to less than 5m so I
don't know if you could detect any minute error anyway without putting it on
an optical bench. If it still worries you, you could send a mail off to
customer service for an opinion? They can certainly put it on their test rig
for you. They checked my 50 and 75 for me in half an hour while I was in
Solms.
Andrea.Frankl at leica-camera.com is the lady to talk to in English.



2009/8/10 Richard Man <richard.lists at gmail.com>

10 kilometers is... 6.21371192 miles. I doubt it makes any difference
> whether you nudge that last mm or not, the DOF will make that
> irrelevant.
>
> But I believe it has to do with heat tolerance or something? Anycase,
> don't worry about it..
>
> On Sun, Aug 9, 2009 at 9:38 AM, Nathan Wajsman<photo at frozenlight.eu>
> wrote:
> > ....namely, it focuses beyond infinity. I discovered it by coincidence
> > today. When I focus on something very far (>10 km away) with my 3.8/24mm,
> > the rangefinder image is in focus at a point just short of the infinity
> mark
> > on the lens. None of my other lenses does that, so the problem is with
> the
> > 24mm.
> >
>
>
>
> --
> // richard m: richard @imagecraft.com
> // w: http://www.imagecraft.com/pub/Portfolio09/ blog:
> http://rfman.wordpress.com
> // book: http://www.blurb.com/bookstore/detail/745963
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information
>



-- 
Cheers
Geoff
Alles was eine gute Kamera braucht / Everything a good camera needs:

http://gallery.leica-users.org/v/gh/
http://www.pbase.com/hoppyman



-- 
Cheers
Geoff
Alles was eine gute Kamera braucht / Everything a good camera needs:

http://gallery.leica-users.org/v/gh/
http://www.pbase.com/hoppyman


Replies: Reply from mark at rabinergroup.com (Mark Rabiner) ([Leica] 24mm lens has incredible powers...)
In reply to: Message from photo at frozenlight.eu (Nathan Wajsman) ([Leica] 24mm lens has incredible powers...)
Message from richard.lists at gmail.com (Richard Man) ([Leica] 24mm lens has incredible powers...)
Message from hopsternew at gmail.com (Geoff Hopkinson) ([Leica] 24mm lens has incredible powers...)