Archived posting to the Leica Users Group, 2010/09/07

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Subject: [Leica] is this a bad pixel? (the bad kind of red dot)
From: photo.forrest at earthlink.net (Phil)
Date: Tue, 7 Sep 2010 19:33:41 -0400
References: <4C86B3A3.2010001@panix.com> <4C86C7C6.4080705@panix.com>

This looks like a bad pixel to me. Like the green and blue channels are
lost at that one site. The one I have in my M8 is pure white, so it's
not the same thing exactly, but if it's reproduced in every frame,
that's probably what you have. My bad pixel only appears in frames that
are underexposed in the particular region where the spot is. If there
is enough signal excess to excite the pixel (I don't know the
threshold) it won't show up at all.

Phil Forrest


On Tue, 07 Sep 2010 19:16:22 -0400
Rei Shinozuka <shino at panix.com> wrote:

>   1. I should have noted, the camera in question that produced the 
> images is a Leica M9.
> 2. also, RAW pictures show the same anomaly.
> 3. finally, i can just shoot f16 1/4000 second and the image is all 
> black, but the red pixel appears. to me, that rules out dust or
> reflections.
> 
> thanks,
> 
> -rei
> 
> 
> On 09/07/2010 05:50 PM, Rei Shinozuka wrote:
> >  is this a bad pixel?
> >
> > http://gallery.leica-users.org/v/shino/techie/L1033797.JPG.html
> >
> > blow up to 100%, there's a red dot between the kitten's chin and
> > the pile of clothing at the bottom side of the window sill.
> >
> > i previously posted this picture of my daughter:
> >
> > http://gallery.leica-users.org/v/shino/portraits/L1033662.JPG.html
> >
> > to the left of my daughter kitty, there's an acorn on top of the
> > wall she's sitting on.  on the top row of "bricks" almost directly 
> > underneath the acorn, 4-5 inches under the top of the wall, there's 
> > the same red dot.
> >
> > it appears in other photos in the same spot.  i think it only
> > appeared in the past week or so, but i've missed it until today.
> >
> > is this a bad pixel?
> >
> > thanks
> >
> > -rei
> >
> >
> > _______________________________________________
> > Leica Users Group.
> > See http://leica-users.org/mailman/listinfo/lug for more information
> 
> _______________________________________________
> Leica Users Group.
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In reply to: Message from shino at panix.com (Rei Shinozuka) ([Leica] is this a bad pixel? (the bad kind of red dot))
Message from shino at panix.com (Rei Shinozuka) ([Leica] is this a bad pixel? (the bad kind of red dot))