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Hot pixel


Max Alfy

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Thank you all on the forum for your valuable expertise. It encouraged me to trade my M6TTL plus some change against a chrome M8 in February; I kept my M2 just in case…

 

The M8 is definitely a great camera, but I have one problem, noticed right from the beginning:

 

On all the JPEG files, there is a “hot pixel”. It is always at the same place: pixel 935 H:1968 V as measured under Photoshop CS2. I can trace the hot pixel in ALL the photos, except if the area is totally white (255,255,255).

 

On the DNG files, this problem is less apparent, but again once you know where it is situated, it can often be found, in the darker areas. It appears on the photos not as a hot pixel, but rather as a lighter 1 pixel wide vertical line spanning the lower 1/3rd or so of the frame.

 

Full size picture and location of the hot pixel. This is my first shot with the M8, straight after the first battery charge!

http://www.leica-camera-user.com/images/attach/jpg.gif

http://www.leica-camera-user.com/images/attach/jpg.gif

 

 

Zoom on the hot pixel

http://www.leica-camera-user.com/images/attach/jpg.gif

http://www.leica-camera-user.com/images/attach/jpg.gif

 

 

Zoom on how the hot pixel typically shows up on a DNG file, converted using Adobe Camera Raw. The 1 pixel wide line can cover 1/3 of the picture.

 

http://www.leica-camera-user.com/images/attach/jpg.gif

http://www.leica-camera-user.com/images/attach/jpg.gif

 

Note: On the M8 screen (PLAY), the hot pixel shows up as a bright dot 100% of the time, whether DNG or JPEG, which is normal since the display is JPEG anyway.

 

The hot pixel does not appear on totally black pictures (lens cap on, yes it happens!): I suppose therefore that it is related to the sensor and that pixel’s reactivity to light: It does not react to absolute darkness.

 

I e-mailed Leica Customer Service on April 19th, but received no reply as of today: I therefore hope that they read the forum from time to time!

 

I found another similar issue in the forum, how was it solved?

 

To Solms or not to Solms, that is the question.

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If you read the Kodak sensor spec, it allows for 2500 out of spec pixels (with additional limits on the number and size of clusters and columns).

 

My undertstanding it that these are meant to be mapped into the firmware as part of the manufacturing process so that the DSP interpolates across them. The Epson R-D1 has a manual process for mapping them out but I do not know how it's done on the M8.

 

It may be your camera needs to go through this process again...

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Thank you for your speedy info, Mark.

 

So it would mean that the M8 should spend some time in Solms for that single pixel!

I guess I'll wait until the turnaround improves, I am addicted to this camera.

 

Max

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