Archived posting to the Leica Users Group, 2007/04/25

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Subject: [Leica] Strange M8 artifact
From: don.dory at gmail.com (Don Dory)
Date: Wed Apr 25 14:50:15 2007
References: <W286416247284351177529021@webmail30>

Ken,
Not to minimise the potential problem, but here in the South it just looks
like she wears short sleeve clothes most of the time and her tan line is a
little uneven.  To replicate, try shooting some white seamless where any
change will be obvious.  Or possibly a black polyester textile that covers
the full frame at two meters.

On 4/25/07, Ken Iisaka <ken@iisaka.org> wrote:
>
> I recently encountered a strange M8 imaging artifact in which two halves
> of the sensor appear to have different sensitivity characteristics.
>
> http://gallery.leica-users.org/v/kiisaka/LeicaM8/RachelSirois.jpg.html
>
> In this photograph (cropped slightly from the original), the shadow level
> is slightly higher, and slightly more magenta in the bottom half (or the
> right half) of the sensor than the top or left half. If you look using a
> carefully adjusted monitor, you will see the line just below the pendant,
> which is exactly 1952 pixels (3904 / 2) from the top, exactly at the middle
> of the sensor, in the original.
>
> Has anyone noted anything like this? My hypothesis is that the overblown
> areas from the window is affecting the circuitry for the one half of the
> sensor. This problem was observed in three nearly identical shots that were
> taken within 10 seconds of each other.
>
> The camera was M8, firmware 1.102, Summilux-M 35mm ASPH, B&W 486 filter
>
> I will conduct more tests to see if I can replicate this problem.
>
>
>
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>



-- 
Don
don.dory@gmail.com

In reply to: Message from ken at iisaka.org (Ken Iisaka) ([Leica] Strange M8 artifact)