Archived posting to the Leica Users Group, 2008/04/20

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Subject: [Leica] Noctilux DOF Film vs M8/test
From: kididdoc at cox.net (Steve Barbour)
Date: Sun Apr 20 07:24:29 2008
References: <D66AF68A-F211-47AA-A589-492C18022D56@comcast.net> <77F7A2BB-2C7C-481D-860C-6C16A64EBF2F@cox.net> <11976B8B-6F3A-41E7-A69B-63063C7AFEE3@pix-that-stimulate.com>

I wonder if someone (maybe Tarek, Len) would suggest a very simple  
formal test setup (the most basic) for this purpose, to run a few  
lenses thru...?

my own testing is at best rudiimentary, as I test by actiually  
shooting,  but I'd like to do a limited amount of formal testing,

thanks, Steve

On Apr 20, 2008, at 7:17 AM, Tarek Charara wrote:

> I must be lucky... All of my lenses did fine wide open with the M8...
>
> All the best from the south of France!
>
> Tarek
>
> -------------------------------------------------
> Tarek Charara
> <http://www.pix-that-stimulate.com>
>
> NO ARCHIVE
>
>
> Le 20 avr. 08 ? 16:15, Steve Barbour a ?crit :
>
>>
>> On Apr 20, 2008, at 6:46 AM, Leonard Taupier wrote:
>>
>>> This is a very interesting issue. I don't know if anybody has  
>>> mentioned what happens to the depth of field of the Noctilux, or  
>>> any other lens, in a Leica film camera versus the M8 digital  
>>> camera. It seems that nobody complains about the focus on a film  
>>> body but all kinds of complaints on the M8, especially the  
>>> Noctilux, Summilux Asph and the 75mm Summilux. Is there a  
>>> difference? Yup, there sure is. I tested 16 leica lenses for depth  
>>> of field at a distance of 8 feet. I tested 13 of the lenses with  
>>> film using a .85 MP and compared the results to those taken with  
>>> an M8 and a 1.25 Leica magnifier.
>>>
>>> In every case the DOF shifts away from the camera with the M8. In  
>>> other words the lens appears to back focus. The worse lens for  
>>> this shift is the Noctilux. But even on a film camera it is barely  
>>> in focus. The typical back focus shift of any 50mm Leica lens is  
>>> about 4 to 5 inches at 8 feet with the M8. The backward shift of  
>>> the Noctilux is between 8 and 9 inches. This puts the focused  
>>> point of the rangefinder outside the depth of field of the lens.  
>>> The other thing I noticed is the DOF is better centered on the  
>>> older LTM lenses then on the newer lenses. I don't know if this is  
>>> a quality control problem now or if the focus point test has  
>>> changed. I tested 7 LTM lenses, the Xenon, Summarit, Summitar,  
>>> Summicron Coll, 50 Elmar RS, 90 Elmar and 135 Hektor. The focus  
>>> point nicely stayed within the DOF on both cameras. Of the M  
>>> lenses the best is the 1st 50mm Summicron rigid version followed  
>>> by the current 50mm Summicron.
>>>
>>> I verified my results with a second M8. The MP body is one year  
>>> old and purchased new. I also sent my Noctilux and 75mm Summilux  
>>> to DAG for focus adjustment even though the lens is still in  
>>> warranty. I'm also shooting more with film these days.
>>
>> hi Len,
>>
>> is it appropriate to send a Noctilux to DAG for focus adjustment,  
>> without the body...
>>
>> does that work out OK?
>>
>> I agree that with film (bodies) I did fine with the Noctilux wide  
>> open, with the M8 much less so...
>>
>> Steve
>>
>>
>>>
>>>
>>> Len
>>>
>>>
>>>
>>> _______________________________________________
>>> Leica Users Group.
>>> See http://leica-users.org/mailman/listinfo/lug for more information
>>
>> best, Steve
>>
>>
>> "I never wanted to be famous"
>> http://www.blurb.com/bookstore/detail/186890
>>
>>
>> _______________________________________________
>> Leica Users Group.
>> See http://leica-users.org/mailman/listinfo/lug for more information
>
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information

best, Steve


"I never wanted to be famous"
http://www.blurb.com/bookstore/detail/186890



Replies: Reply from abridge at gmail.com (Adam Bridge) ([Leica] Noctilux DOF Film vs M8/test)
Reply from len-1 at comcast.net (Leonard Taupier) ([Leica] Noctilux DOF Film vs M8/test)
In reply to: Message from len-1 at comcast.net (Leonard Taupier) ([Leica] Noctilux DOF Film vs M8)
Message from kididdoc at cox.net (Steve Barbour) ([Leica] Noctilux DOF Film vs M8)