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[OM] Re: Anomalies in E-1/OM Images -- Update

Subject: [OM] Re: Anomalies in E-1/OM Images -- Update
From: Cyrtolite@xxxxxxx
Date: Thu, 13 May 2004 20:20:35 EDT
Thanks for the reply, Wayne.

I shoot raw.  I almost never shoot JPEG.  With the E-1 you can also shoot 
directly to TIFF. I used Photoshop's unsharp mask tool for the sharpening 
(500%, 
3 pixels radius, threshold anywhere from 0 to 10 levels).  The spots are 
visible before sharpening and some of them are too large to be a sharpening 
artifact. Sharpening just makes some of them easier to see.  I see no signs of 
dead 
pixels. I think they'd be pretty easy to see at 100-200%. 

I suppose clusters of dead pixels could be on the right scale but I would 
expect dead pixels to occur randomly (though differential heating or something 
like that could cause them to occur preferentially in a particular part of the 
sensor). The spots are about perfectly circular and the larger ones are 
composed of concentric rings.  It's hard to imagine how this kind of symmetry 
could 
result from sharpening around random defects.

I wonder if any other E-1 users are seeing anything like this.  Of course, I 
guess they wouldn't notice them unless they were using a long OM lens or a 
bellows.

Thanks again.

Scott Whittemore

-----------------------Original Message-----------------------

To: olympus@xxxxxxxxxx
Subject: [OM] Re: Anomalies in E-1/OM Images -- Update
From: W Shumaker <om4t@xxxxxxxx>
Date: Wed, 12 May 2004 17:08:34 -0400

>Did you shoot raw or jpeg, and what was the sharpening set to?
>I wonder what sharpening does if you have pixel mapping, where
>dead pixels are mapped over with interpolation? Raw does not
>sharpen, unless you do it in post processing. Most forms of sharpening
>will over shoot around tonal transitions. If there was a bug in the
>software, it might try sharpening around a dead pixel (not likely,
>just a thought). Or it could be overshoot in the interpolation around
>a dead pixel???

>Wayne


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