Archived posting to the Leica Users Group, 2001/11/26

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Subject: Re: [Leica] RE: adapter ring:plot thickens
From: "Mark Pope" <mark.teampope@ntlworld.com>
Date: Mon, 26 Nov 2001 21:03:54 -0000
References: <140.52cb765.2932982d@aol.com>

Hi Seth,

Odd one this.  Out of purely academic interest and because I had nothing
better to do (nothing worth watching on TV and not feeling like going in the
darkroom), I checked my Voigtlander 21mm and LTM adaptor, comparing it with
a 35mm summicron.  I used a 0.72 magnification M6TTL for the comparison.
First off, I tried focusing both lenses on an object that was reasonably
close (2m), reasoning that if there was a problem at infinity, then the
problem would also exist throughout the focusing range. After focusing, I
checked the scales of the lenses - both said 2m.  So no problem there.  I
then took the camera outside. I focused  both lenses on the brightest star I
could see.  Again, both lenses were fine, with no movement beyond infinity.

By my reckoning, and given that you have tried other Voigtlander adaptors,
then there are two other possible causes:

1. the focus of your 21mm lens is mis-calibrated;
2. there is a problem with the rangefinder cam in your M6 - have you noticed
whether any of your other lenses exhibit this trait?

BTW - focusing on stars is a great way of checking vertical alignment of
RFs!

Well, that's my 10p worth.  I hope it helps.

Regards


Mark Pope
Swindon, Wilts
UK

http://www.monomagic.co.uk





- ----- Original Message -----
From: <SthRosner@aol.com>
To: <leica-users@mejac.palo-alto.ca.us>
Sent: 25 November 2001 18:53
Subject: Re: [Leica] RE: adapter ring:plot thickens


> oh-oh. Ten days ago I bought a new Voigtlander-Cosina 21mm Color-Skopar
AND A
> LEICA SCREW-TO-M adapter. On my M6, at the full infinity stop of thge
lens,
> the lens cam has pushed the M6 RF image beyond infinity. I thought it was
a
> defect in the lens. But the vendor checked  a Leica adapter on three other
> V-C lenses with the same result.
>
> The conclusion is obvious: the Leica adapter is not of the correct
thickness
> and thus, the lens cam does not take the correct position relative to the
> camera probe/arm. I'm trying to get a V-C adapter to see if in fact it
aligns
> the lens cam and and the M6 probe correctly.
>
> Seth        LaK 9
> --
> To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html
>

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In reply to: Message from SthRosner@aol.com (Re: [Leica] RE: adapter ring:plot thickens)