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

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Subject: [Leica] Noctilux DOF Film vs M8/test
From: len-1 at comcast.net (Leonard Taupier)
Date: Sun Apr 20 08:08:19 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> <3C12593D-C242-41C2-8ADA-56E08C97BBE2@cox.net>

The most simple of tests would be to photograph a yardstick, with  
clear numbers, standing on edge and placed at a 45 degree angle to  
the M8 on a tripod. The yardstick and camera lens should be at the  
same plane and at a distance you can still read the numbers. I use  
between 7 and 8 feet. Place a thin, vertical object in the middle of  
the yardstick to use as a focus point.  You may not be happy with the  
results so if you're happy with your photos and lenses now don't do  
the test.

Len


On Apr 20, 2008, at 10:24 AM, Steve Barbour wrote:

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



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)
Message from kididdoc at cox.net (Steve Barbour) ([Leica] Noctilux DOF Film vs M8/test)