Archived posting to the Leica Users Group, 2011/03/19

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: [Leica] New portrait of my son added today
From: photo at frozenlight.eu (Nathan Wajsman)
Date: Sun, 20 Mar 2011 07:37:33 +0100
References: <C9AB169E.4483C%chris@chriscrawfordphoto.com>

Thanks for the explanation, Chris. So basically the lens is systematically 
defective--I am surprised that a company like Zeiss would bring such a 
product to market.

Cheers,
Nathan

Nathan Wajsman
Alicante, Spain
http://www.frozenlight.eu
http://www.greatpix.eu
http://www.nathanfoto.com
PICTURE OF THE WEEK: http://www.fotocycle.dk/paws
Blog: http://www.fotocycle.dk/blog

YNWA







On Mar 20, 2011, at 7:27 AM, Chris Crawford wrote:

> Nathan and Ted,
> 
> The Zeiss ZM 50mm f1.5 C-Sonnar is well known to suffer from a pretty 
> severe
> focus shift as you stop down. The point of sharpness moves back as you stop
> down.
> 
> Zeiss originally sold them with the focus cam set so that focus, as seen
> through your camera's rangefinder, was correct when the lens was set at
> f2.8. At smaller apertures, depth of field was enough that the shift didn't
> keep the focused subject from being sharp, but at f1.5 and f2 the lens 
> would
> front focus (quite a bit at f1.5).
> 
> People complained that the lens wasn't sharp at f1.5, which is untrue. It 
> IS
> sharp at f1.5, IF the lens is adjusted to be in focus at f1.5, so later 
> ones
> were sold by Zeiss set for f1.5. This makes them unusable at smaller
> apertures till you stop down quite a bit, from what I've seen online.
> 
> I know with mine, which is set for f2.8, the lens is not usable at f2 or
> f1.5, which does not bother me as I wanted it for portraits and I never do
> portraits wider than f2.8. Some of the people on rangefinderforum claim the
> lens is perfectly fine at f1.5 with one set for 2.8, you just have to 'lean
> in' a bit to compensate for the front focusing at wider apertures, but I
> hate guessing-games like that. I need stuff that 'just works' so I use it 
> at
> the apertures it 'just works' at. F2.8 and below.
> 
> To reiterate, the focus shift is real, despite what some of the 
> know-it-alls
> online claim. For some reason some people think it makes them look smart to
> claim that focus shift in some lens designs is an 'internet delusion',
> despite Zeiss saying that the C-Sonnar does this, and despite the fact that
> testing it is not hard and shows the shift to be there. I have tested my
> lens extensively, and the shift is severe at f1.5 and at f2 its enough to
> make the photo still look too soft. This lens is capable of being VERY 
> sharp
> when used correctly. I think mine is sharper in the senter at f2.8 than my
> 50mm tabbed Summicron, though the Summicron is a lot sharper in the corners
> at that aperture. Stopped down a couple more stops, they're equally good
> across the full frame.
> 
> 
> -- 
> Chris Crawford
> Fine Art Photography
> Fort Wayne, Indiana
> 260-486-2581
> 
> http://www.chriscrawfordphoto.com  My portfolio
> 
> http://blog.chriscrawfordphoto.com  My latest work!
> 
> http://www.facebook.com/pages/Christopher-Crawford/48229272798
> Become a fan on Facebook
> 
> 
> 
> 
> 
> On 3/20/11 2:03 AM, "tedgrant at shaw.ca" <tedgrant at shaw.ca> wrote:
> 
>> Nathan Wajsman ASKED?
>> Subject: Re: [Leica] New portrait of my son added today
>> 
>> 
>>> Nice portrait, but how do you know that a particular lens is optimized 
>>> for
>>> a particular aperture?<<<<
>> 
>> Hi Nathan,
>> You beat me to the very question? :-)
>> 
>> Hi Chris,
>> How was this setting established? What kind of measurement method did you
>> use? Or who and how was it determined that f.2.8 was the optimum aperture?
>> 
>> Thanks,
>> Dr. ted
>> 
>> 
>> 
>>> On Mar 19, 2011, at 5:28 PM, Chris Crawford wrote:
>>> 
>>>> http://tinyurl.com/mack30811
>>>> 
>>>> I shot this one a couple weeks ago with the 50mm C-Sonnar. Mine's
>>>> optimized
>>>> for f2.8, which is the aperture I used.
>>>> 
>>>> 
>>>> -- 
>>>> Chris Crawford
>>>> Fine Art Photography
>>>> Fort Wayne, Indiana
>>>> 260-486-2581
>>>> 
>>>> http://www.chriscrawfordphoto.com  My portfolio
>>>> 
>>>> http://blog.chriscrawfordphoto.com  My latest work!
>>>> 
>>>> http://www.facebook.com/pages/Christopher-Crawford/48229272798
>>>> Become a fan on Facebook
>>>> 
>>>> 
>>>> 
>>>> _______________________________________________
>>>> 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
>> 
>> 
>> _______________________________________________
>> 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
> 



Replies: Reply from chris at chriscrawfordphoto.com (Chris Crawford) ([Leica] New portrait of my son added today)
In reply to: Message from chris at chriscrawfordphoto.com (Chris Crawford) ([Leica] New portrait of my son added today)