Odd pixel

Moab Man

Senior Member
Shooting with my Nikon DF in Raw/jpeg to have instant photos to pull off and I have this pixel showing up. It's not a sparkly on his face. It's in every jpeg at the same exact place. However, it's not in any of the raw files. STUMPED!

Anyone have any ideas?

Pixel_DFG_3672.jpg
 
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Dawg Pics

Senior Member
Learn me something.
Hot pixel is what it looks like, and that is what I would have guessed, but why does it show up only in the jpeg image?
 

480sparky

Senior Member
Not all raw converters are the same. What's built into the camera can demosaic the raw data differently than an engine used in a computer app. So maybe the in-camera algorithm fails to detect it and causes the green dot, but the computer's app does and removes it.
 

Moab Man

Senior Member
I thought hot pixel as well, but the not showing up in raw files doesn't make sense. And I'm not saying Sparky is wrong, but I haven't heard of Nikon cameras cancelling out hot pixels before.
 

Dawg Pics

Senior Member
I thought hot pixel as well, but the not showing up in raw files doesn't make sense. And I'm not saying Sparky is wrong, but I haven't heard of Nikon cameras cancelling out hot pixels before.

Well, then someone's got some 'splanin' to do.;). When you find out, please let me know. I read up on hot pixels a long time ago, but I don't remember what I read.

Edit: I just read something that ACR and LR maps out hot pixels whatever that means. What progam are you using?
 
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480sparky

Senior Member
I thought hot pixel as well, but the not showing up in raw files doesn't make sense. And I'm not saying Sparky is wrong, but I haven't heard of Nikon cameras cancelling out hot pixels before.

You never look at raw files. They're converted to jpegs so you can see them. Either in-camera or in-computer.
 

Moab Man

Senior Member
Hmm, my post didn't show up from last night. I found a number of locations all stating that ACR does get rid of hot pixels when importing. Learned something new.
 

spb_stan

Senior Member
All sensors have hot pixels but are mapped out at the factory so they are not seen in either RAW or JPG. If a pixel fails after leaving the factory, it can be mapped out at any Nikon service center. Many brands allow you to map out hot or dead pixels but Nikon does not.
With any device with 10s of millions of semiconductor elements like transistors, a few are bad so provisions are made to improve yields by being about to burn lookup tables to ignore that defective cells or transistors. Memory chips would be much more expensive if each had to be 100% functional. But mapping out those defective transistors from the addressing tables, the chip is still perfectly usable. Same with hard drives and SSD drives and camera sensors.
 
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