Archived posting to the Leica Users Group, 2010/11/18

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

Subject: [Leica] Canon non-linear metering
From: leicar at (Aram Langhans)
Date: Thu, 18 Nov 2010 09:05:58 -0800
References: <>

OK.  Here is a quick demonstration of what a Canon camera does with a Leica 
lens as far as metering goes.

Nothing fancy, just the wall in my room.  Shot raw on my Rebel XTi with 
absolutely no post processing, so not very photogenic, but gets the point 

Set camera to Aperture priority mode.  Opened lens, 50 Sumicron, to 2.0 and 
took a shot.  Meter showed as centered.  Stopped down one stop and took 
another, meter still showing as centered.  Repeated all the way to f-ll, and 
meter still shows the camera is picking an appropriate shutter speed to keep 
meter centered.  As you can see, from f-4 on, the meter is not choosing the 
correct shutter speed.  It starts to over expose and continues to do so more 
and more.  If I had gone to f-16, it would be even more overexposed.

So, the only way to get consistent results is to meter wide open in manual 
mode, then count down to the f-stop you want, and adjust the shutter the 
same number of counts, ignoring what the meter is telling you.  It will say 
you are underexposing the shot, but it will be the correct exposure when you 
see the picture.



> From: Tim Gray <tgray at>
> Subject: Re: [Leica] DMR or Nikon D700 and Leitax adapters
> To: Leica Users Group <lug at>
> Message-ID: <20101118035639.GD60960 at>
> Content-Type: text/plain; charset=us-ascii; format=flowed
> On Nov 17, 2010 at 10:03 PM -0500, Vick Ko wrote:
>> I'm going to have to educate myself on the "non-linear exposure issues".
>> Sounds like a PITA.
> Yes.  Info?  Links?

Replies: Reply from at (Douglas Sharp) ([Leica] Canon non-linear metering)
Reply from imagist3 at (George Lottermoser) ([Leica] Canon non-linear metering)
Reply from tgray at (Tim Gray) ([Leica] Canon non-linear metering)
Reply from vick.ko at (vick.ko at ([Leica] Canon non-linear metering)