Archived posting to the Leica Users Group, 2009/05/22

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Subject: [Leica] 90 APO Asph on M8
From: mingthein at gmail.com (Thein Onn Ming)
Date: Sat, 23 May 2009 14:03:50 +0800
References: <mailman.912.1243041579.1139.lug@leica-users.org> <7515F759-A92D-43A6-AF64-2FD180833ECE@netvigator.com> <63BD3033-C034-4FA1-B8DC-8796E2DE4320@gmail.com> <p0623090ec63d3f25864a@[10.0.1.199]>

Too late. :P Already did it with the 90 pre AA I had; tweaked a  
little for the 50/1.5 nokton, and now everything's bang on.

Actually, I admit it's not the first time I've played with focusing  
alignment. I've had to tweak the submirror and mirror rest position  
on most of my Nikons for critical MF, as well as adding a shim or two  
to the focusing screen. First time with an RF though, but I suspect  
the concept is similar in principle.

Ming

On May 23, 2009, at 1:57 PM, Henning Wulff wrote:

> At 1:44 PM +0800 5/23/09, Thein Onn Ming wrote:
>> Have you tried that 2mm hex wrench tweak? There's a little bolt  
>> inside the roller cam that can be easily adjusted for front/back  
>> focus. After adjusting my 90 pre AA cron for infinity focus with  
>> the cam (set the lens barrel to infinity, pick a really distant  
>> object like a mountain range >20km away and adjust for overlap),  
>> everything was a bit easier. My problem was that my eyes aren't  
>> quite good enough to overlap the RF patch precisely if there isn't  
>> a sharp line or two in the scene.
>>
>> Ming
>>
>
> I would advise against trying to adjust for the 90 AA in that way.  
> Firstly, it could very well be the 90 that is the problem.  
> Secondly, if you fiddle with the infinity setting for one lens, the  
> close up performance with it, and all other lenses could suffer.  
> The adjustment is quite unforgiving with the longer faster lenses,  
> and my advice is to give it to someone who has experience and the  
> equipment to do a full adjustment.
>
> As Howard Cummer has mentioned, I had issues with my 90 and I  
> considered sending it and a camera to get adjusted, but by that  
> time I realized that I was shooting more with my 75's anyway. I did  
> send off one camera and some fast lenses including the Noctilux to  
> Solms last year along with some other lenses getting coded, and  
> everything came back in fine adjustment. I can now focus the  
> Noctilux accurately wide open on both cameras, as well as the  
> 75/1.4. It was worth the effort and money (and the anxiety in  
> sending all those many items off in a little parcel).
>
> -- 
>
>    *            Henning J. Wulff
>   /|\      Wulff Photography & Design
>  /###\   mailto:henningw at archiphoto.com
>  |[ ]|     http://www.archiphoto.com
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information

THEIN Onn Ming
*photohorologer ming at www.mingthein.com
www.flickr.com/mingthein







Replies: Reply from henningw at archiphoto.com (Henning Wulff) ([Leica] 90 APO Asph on M8)
In reply to: Message from cummer at netvigator.com (H&ECummer) ([Leica] 90 APO Asph on M8)
Message from mingthein at gmail.com (Thein Onn Ming) ([Leica] 90 APO Asph on M8)
Message from henningw at archiphoto.com (Henning Wulff) ([Leica] 90 APO Asph on M8)