Dead Pixel on Camera?
3251 9 2016-5-10
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Infinite loop
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Philippines
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Guys its 4 days old P4 and first time to do night flight. I was shocked seeing this photo with look like dead pixels after importing my images to my PC.
Please check the DNG files guys. Thanks in advance.

DNG File



2016-5-10
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jwt873
Second Officer
Flight distance : 6754350 ft
Canada
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Actually, that's pretty normal for a dark frame shot like that.   DJI has software (Called DJI DNG Cleaner) to remove the dots..   You can download it here -->>  https://www.dji.com/product/phantom-4/info#downloads
2016-5-10
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Infinite loop
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jwt873@gmail.co Posted at 2016-5-10 23:48
Actually, that's pretty normal for a dark frame shot like that.   DJI has software (Called DJI DNG C ...

thanks jwt873 for fast reply, already download the DNG cleaner and tried but still same result. Or its just me who don't know to set the camera setting at night?
2016-5-10
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Aardvark
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Flight distance : 384432 ft
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I've just seen the image and what you are seeing  are called 'hot pixels', every imaging device will have some & occasionally more than some. Probably taken on highest ISO and long exposure ?
These are more often seen in Astronomy imaging where some very long exposures are used (20-30 minutes is not untypical for the shutter to be open).
One technique that astronomers use is to 'dither' the images slightly i.e. move the camera very slightly and take another image, and so on. These images can then be stacked to keep the meaningful data but getting rid of noise and eliminate hot pixels on the final image.
2016-5-10
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jwt873
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I've never taken such a dark image..  I figured the cleaner utility would help, but I guess it doesn't.

There are other methods.  One is using 'dark frame subtraction'.  You take a shot with the lens completely covered producing a black image.  The hot pixels will show up there.   Then you use software to map the position of the stuck pixels on the black image and use that to remove the corresponding ones from images you want.  

There are several ways to do this...  Here's one site that gives an overview..  http://www.takegreatpictures.com ... -br-by-chris-limone
2016-5-10
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Aardvark
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jwt873@gmail.co Posted at 2016-5-10 17:47
I've never taken such a dark image..  I figured the cleaner utility would help, but I guess it doesn ...



With dark frame subtraction the darks should be taken at same exposure length & ISO setting as the original, and ideally at similar ambient temperature. If not they can just add additional noise to the image.
2016-5-10
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DJI-Paladin
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Flight distance : 2408 ft
Hong Kong
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I think you can try to take some photos in well-lighted area to test the "Dead point". And DNG cleaner are usually used to clean some blue or red points on the DNG files.
2016-5-10
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Infinite loop
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Alright guys i will update the result later soon i get home. I really appreciate the support you've given to a newbie like me ;)
2016-5-10
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ferventjan
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Indonesia
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I have the same problem as well, can anyone please help me identify what might cause this? I never crashed or hard landing.

JPG File
2017-3-8
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fansa84fe8a4
Second Officer
Flight distance : 3 ft
United States
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ferventjan Posted at 2017-3-8 18:16
I have the same problem as well, can anyone please help me identify what might cause this? I never crashed or hard landing.

JPG File

Try using another converter for your image.

RawTherapee 5 is freeware but probably the most powerful RAW processor on the market.  Just open your DNG file in it and see how it looks in the sky portion with those bands.  Ignore all the other stuff for the time being as the program is complex enough for a PhD.

If it shows the banding in it as well, then your camera is probably toast.

Good luck!
2017-3-9
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