Archived posting to the Leica Users Group, 2007/07/29

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Subject: [Leica] Licanon Exposure Question
From: telyt at earthlink.net (Douglas Herr)
Date: Sun Jul 29 14:52:27 2007

Leonard Taupier <len-1@comcast.net> wrote:

>I found your findings quite interesting so I ran my own test. I used  
>the same lens, the 35-70/4 (6 months old, latest version) mounted on  
>a 20D with a Novoflex adapter. I got pretty much the same results you  
>did. The exception is at f4 the exposure started at 1 stop  
>underexposed. Starting at f4 and stopping down in full stops the  
>shutter speeds were 1/1000, 1/400, 1/160, 1/60, 1/30, and 1/15 at f22.
>
>I ran the same test on my R8 but got perfect exposure across all f  
>stops. The results were 1/500, 1/250, 1/125, 1/60, 1/30, and 1/15.
>
>This is pretty strange. It's a misty day today so the light is fairly  
>uniform. My test was done at 70mm and ISO 400. I confirmed my  
>readings with my M7 and 75mm lens. The results were identical to the R8.

It's a known problem with this camera using non-CPU lenses & stop-down 
metering.  It has to do with the screen brightening process used to 
compensate for the light diverted from the viewfinder for the AF system.  
Doncha luv AF?


Doug Herr
Birdman of Sacramento
http://www.wildlightphoto.com

Replies: Reply from len-1 at comcast.net (Leonard Taupier) ([Leica] Licanon Exposure Question)