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P2V+ Bright Spot in video, not stills, non-moving

Discussion in 'Phantom 2 Vision + Discussion' started by RScottCampbell, May 16, 2014.

  1. RScottCampbell

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    Hi gang,

    In the video taken on my P2V+ I have a non-moving, bright spot roughly in the top 7/8ths & center of the frame. It appears at all shooting angles, in all light, and at all directions from the light source. However, it only shows in video not in stills. It shows on all my computers and on my FPV device. It doesn't move about like lens flare or oppositional glare. As the scene moves it stays put.

    Has anyone experienced this? Any ideas? I've contacted DJI support and they aren't responding.

    Here are a couple of links to zip files of two videos I shot that show it. It especially shows in flat, solid color spaces. (note these are good sized files, 600 mb and 800 mb, I zipped them so they would be downloadable for DJI support.)

    http://www.scottcampbellphotography.com/downloads/DJI/RScottCampbellSpotTest_1.zip

    http://www.scottcampbellphotography.com/downloads/DJI/RScottCampbellTestShot-2.zip

    I've also attached a couple of screen grabs from the above files.






    Thanks for any help/ideas.
     

    Attached Files:

  2. Birdman

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    I see the spot, and it's not normal. It may be in the processing, rather than in the camera, since it doesn't show up in stills. Typically, spots of this sort are caused by a dust speck on the sensor. but should show up on video or still. It becomes more obvious with small f stops. Have you checked recording videos in different resolutions? Try 1080p. I think more information/tests are needed before a cause can be found. Good luck.
     
  3. RScottCampbell

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    Hi Birdman,

    That's a good thought. Dust on the sensor. Going with that theory, I did a test, flat monochrome surface, shot all video modes and a still. I moved the camera around so I could see the spot better. And...

    The spot grows in size as the video resolution lowers. As the FOV lowers or the frame ratio changes the spot also changes position.

    Since even the 1080 sized video resolution is about 1/4 the size of the still image resolution, the spot would be far smaller and maybe even barely noticeable in a still. I looked closely at my still of the same subject and "maybe" there's a bright spot... maybe.

    Tomorrow I'll take it out and try in a well light setting and the right type of color, i.e. a blue sky. Then I'll report back.

    I'm thinking your dust on the sensor theory might be right.

    Anyone know if these sensors can be accessed? That might have to be another thread.
     
  4. Dirty Bird

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    My camera has a couple bright pixels. These are individual pixels, and I have not changed FoV to see if it alters their size. A simple test to check for bright/dark pixels would be to take a shot of a solid white object to test for dark pixels, and a shot in total darkness to test for light pixels.
     
  5. Birdman

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    Good procedure, but his spot is way too big, and too dispersed to be a pixel problem. Usually dust on the sensor produces a dark spot, not white, so not sure what RScottCampbell's problem actually is.
     
  6. RScottCampbell

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    I’ve run more tests with identical views at all different video resolutions and shot JPG and DNG of the same image. The only time the bright spot does not show is in the DNG/RAW files and the FOV zoomed in video files. The bright spot seems to be out of the picture on the smaller FOV videos. That leads me believe that this is an image processing issue that is from within the camera processing itself.

    Here’s the link to the files:
    http://www.scottcampbellphotography.com/downloads/DJI/RScottCampbellSpotTest_4.zip
     
  7. Birdman

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    Unable to unzip file. Agree, may well be in processing.
     
  8. RScottCampbell

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    Well DJI finally admits that it's a manufacturer build error. Something in the image processing. The bright spot occurs only on processed images (jpgs) and videos. It does not appear in the DNG files.

    The really big deal is that DJI is sticking like glue to their exchange policy. Even though I have evidence (video and stills) from the day after I purchased the P2V+, I notified them outside the local 10 day window for exchanges so they are refusing to exchange the unit and it has to go in for repair. I had back to back photo shoots and didn't have time to put together samples for them.

    The really, really big deal is that they aren't taking ANY RMA's until June 1st.

    I would think that they would honor the fact that I have evidence that the flaw was there from day one.

    Has anyone else had problems with DJI's level of customer service? Do other makers have better customer service? And do other makers build a better product?