Archived posting to the Leica Users Group, 2007/04/01

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Subject: [Leica] Focus shift on 50/1.4 Nikkor on M8
From: hoppyman at bigpond.net.au (G Hopkinson)
Date: Sun Apr 1 16:23:10 2007
References: <001801c774af$6ab53db0$6501a8c0@asus930> <000801c774b0$a61d9090$44300b44@GATEWAY>

OK, well I think that may add another variable. The focus point may not be 
identical if you change the aperture AFTER focusing. I
thought that the back focus (or front focus) issue was when the rangefinder 
was coincident, at the shooting aperture, but the image
has a different point of sharpest focus? This error would be most visible 
with large apertures, and closer subjects, due to the
inherent lack of DoF?

Cheers
Hoppy


-----Original Message-----
From: lug-bounces+hoppyman=bigpond.net.au@leica-users.org 
[mailto:lug-bounces+hoppyman=bigpond.net.au@leica-users.org] On Behalf Of
Jeffery Smith
Sent: Monday, 2 April 2007 08:54
To: 'Leica Users Group'
Subject: RE: [Leica] Focus shift on 50/1.4 Nikkor on M8

I'm focusing with each shot, and stopping down the aperture one stop at a
time.

Jeffery Smith
New Orleans, LA
http://www.400tx.com
http://400tx.blogspot.com/



-----Original Message-----
From: lug-bounces+jsmith342=cox.net@leica-users.org
[mailto:lug-bounces+jsmith342=cox.net@leica-users.org] On Behalf Of G
Hopkinson
Sent: Sunday, April 01, 2007 5:45 PM
To: 'Leica Users Group'
Subject: RE: [Leica] Focus shift on 50/1.4 Nikkor on M8


Just so we are all on the same page; you guys are setting the aperture, then
focusing with the rangefinder, resulting in the described results?

Cheers
Hoppy

-----Original Message-----
From: lug-bounces+hoppyman=bigpond.net.au@leica-users.org
[mailto:lug-bounces+hoppyman=bigpond.net.au@leica-users.org] On Behalf Of
Jeffery Smith
Sent: Monday, 2 April 2007 06:33
To: 'Leica Users Group'
Subject: RE: [Leica] Focus shift on 50/1.4 Nikkor on M8

I suppose that I should set up some sort of contraption to find the "soft
spots" on all of my lenses. It would have been a prohibitive pain in the ass
without the M8. But the test I ran on the Nikkor tells me that if I took a
portrait of someone at 5' and at f/5.6, her eyes would be out of focus.

For now, I think I need to decide which one of my 28's, 35's, and 50's will
reside most of the time on my M8 and test them.

Jeffery Smith
New Orleans, LA
http://www.400tx.com
http://400tx.blogspot.com/



-----Original Message-----
From: lug-bounces+jsmith342=cox.net@leica-users.org
[mailto:lug-bounces+jsmith342=cox.net@leica-users.org] On Behalf Of Leonard
Taupier
Sent: Sunday, April 01, 2007 3:21 PM
To: Leica Users Group
Subject: Re: [Leica] Focus shift on 50/1.4 Nikkor on M8


Jeffrey,

This is similar to what I see on the Noctilux. Your Nikkor is  
probably on the edge of a back focus point and then shifts at f4. I  
think most lenses focus shift somewhat.

I just checked my 1.5 Summilux.

1.5 Very soft. just out of focus. front focus. some flare.
2.0 Soft (low contrast). just in focus. still front focus.
2.8 -> 16. In focus. sharpens up nicely. focus in center of DOF.

Len


On Apr 1, 2007, at 3:25 PM, Jeffery Smith wrote:

> Well, I wasn't expecting this. Shooting a copper wire about 5 feet 
> from me with the M8 and 50/1.4 Nikkor LTM:
>
> 1.4   In focus but soft
> 2     In focus
> 2.8   In focus
> 4     Slightly out of focus
> 5.6   Even more of of focus(!)
> 8-22  In focus
>
> Optics guys, is this a reasonable result?
>
>
>
> Jeffery Smith
> New Orleans, LA
> http://www.400tx.com
> http://400tx.blogspot.com/
>
>
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information


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



_______________________________________________
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Replies: Reply from Frank.Dernie at btinternet.com (Frank Dernie) ([Leica] Focus shift on 50/1.4 Nikkor on M8)
Reply from jsmith342 at cox.net (Jeffery Smith) ([Leica] Focus shift on 50/1.4 Nikkor on M8)
Reply from len-1 at comcast.net (Leonard Taupier) ([Leica] Focus shift on 50/1.4 Nikkor on M8)
In reply to: Message from hoppyman at bigpond.net.au (G Hopkinson) ([Leica] Focus shift on 50/1.4 Nikkor on M8)
Message from jsmith342 at cox.net (Jeffery Smith) ([Leica] Focus shift on 50/1.4 Nikkor on M8)