Fluctuating exposure levels
2965 27 2016-3-26
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Jimmy James
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Check out this sample. This happened a few times on a flight this evening. Light conditions didn't change and manual video settings were ISO 400 at 1/50 with ND16 filter yet the picture exposure fluctuated as though it were set to automatic. Firmware is up to date. This would be unusable for a film product. Has anyone experience this?


2016-3-26
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Jimmy James
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Could it be the video compression?
2016-3-27
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fhagan02
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Yes I've unfortunately noticed this issue. If the issue is the same as mine - it's like a subtle light pulse on screen? Almost as if the aperture was changing (which is impossible as the camera is a fixed f2.8) Almost like it's on auto mode and the camera is making slight ISO adjustments therefore you get this flicker or quick click, albeit subtle, exposure change?

After lengthy web searches and asking questions it seems to be a limitation of the camera. I thought it had just started doing as sometimes it seems randomly worse... or not apparent at all. Checked some of my first videos with the P3P... it's subtle.... but it was there too. My eyes had become better at noticing detail so it's more obvious to me now.

To my knowledge there is no fix. Short of buying an Inspire with the X5 carmera the P3's camera... is what it is. Sorry I know this isn't the input you're probably hoping for. But perhaps at least some resolution. I spent a full week researching, testing and retesting before I came to this conclusion.
2016-3-27
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fhagan02
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Jimmy James Posted at 2016-3-27 10:13
Could it be the video compression?

I dont' think so. If it were compression you'd first notice artifacts and a breakdown in image clarity and resolution. Your shot here is clean thoughout the entire clip. From my research it does have something to do with the camera's maximum shooting bit rate. The P3P's camera shoots at about 60Mb/s. You think that would be enough to handle processing the image in a constant even stream. (The GoPro Hero 4 has the same sensor, shooting at the same bit rate and doesn't appear to have this issue.) That said broadcast quality footage needs to come from a camera that can shoot 50-100Mb/s. Many have begged DJI to up the camera's bit rate to counteract this "flicker" issue.
2016-3-27
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nigelw
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fhagan02@me.com Posted at 2016-3-27 15:28
Yes I've unfortunately noticed this issue. If the issue is the same as mine - it's like a subtle lig ...

I've never noticed it...maybe I'll start seeing it now.

From your research, is there a possibility it could just be a random problem with some cameras & not others?  Like the problems some are getting with lenses being out of focus/misaligned?
2016-3-27
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Mad_Angler1
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what craft is this

iv been seeing something similar recently
2016-3-27
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Jimmy James
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It's the P4. I've never noticed it on my P3p...
2016-3-27
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rwhoffart
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Something definitely changed. Auto white balance?
2016-3-27
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fhagan02
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nigelw Posted at 2016-3-27 15:09
I've never noticed it...maybe I'll start seeing it now.

From your research, is there a possibilit ...

Not sure but I guess it's possible. Honestly I think it's hard to tell as most folks don't look that closely at the footage... or don't really care. Not judging... just saying. Some are casual flyers and shooters. Others like myself edit and shoot for a living so my eye is much more critical. So it's hard to say exactly how many cameras really have the issue.  That said there's more than one post complaining about this exact problem. So it does exist.
2016-3-28
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Jimmy James
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rwhoffart@gmail Posted at 2016-3-27 21:41
Something definitely changed. Auto white balance?

Damn, it is on auto white balance. I feel like such a noob... I'll switch it and do another test tomorrow. Fingers crossed!
2016-3-28
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MattG
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Jimmy James Posted at 2016-3-28 20:52
Damn, it is on auto white balance. I feel like such a noob... I'll switch it and do another test t ...

How do you switch the auto white balance? I'm having similar issues. Cheers!
2016-3-28
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Geebax
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Jimmy James Posted at 2016-3-29 06:52
Damn, it is on auto white balance. I feel like such a noob... I'll switch it and do another test t ...

You beat me to it, I was going to suggest changing to manual white balance.
2016-3-28
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rwhoffart
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Jimmy James Posted at 2016-3-28 14:52
Damn, it is on auto white balance. I feel like such a noob... I'll switch it and do another test t ...

Please post results
2016-3-29
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rwhoffart
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MattG Posted at 2016-3-28 19:08
How do you switch the auto white balance? I'm having similar issues. Cheers!

at 4:40 in this video

2016-3-29
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MattG
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rwhoffart@gmail Posted at 2016-3-30 01:54
at 4:40 in this video

https://youtu.be/my2cFiPKvao

Thank you!
2016-3-30
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Jimmy James
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Funny, he says auto white balance has been working out for him...
2016-3-30
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Jimmy James
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Auto white balance off = problem solved!

2016-3-30
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nigelw
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Jimmy James Posted at 2016-3-30 13:48
Funny, he says auto white balance has been working out for him...

It'll depend on the scene in front of the camera.  Yours had half blue, half orange, total opposites in terms of white balance.  The camera can only judge what's in view.
2016-3-30
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Jimmy James
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nigelw Posted at 2016-3-30 17:32
It'll depend on the scene in front of the camera.  Yours had half blue, half orange, total opposit ...

That's why auto white balance doesn't work well in motion pictures. Best to set it manually and tweak it in post if necessary.
2016-3-30
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TK-421
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2016-4-4
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rwhoffart
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Jimmy James Posted at 2016-3-31 10:02
That's why auto white balance doesn't work well in motion pictures. Best to set it manually and tw ...

Glad it worked Jimmy!
2016-4-5
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TK-421
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2016-4-8
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Dennis9877
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Sometime the Auto white balance system adjust during movement.  White Balance is a system that tells the camera where white (the presents of all color and Black the absent of all color) begins and ends.  If that setting moves a person may see the change in the video.  The programming should only make the change over a .10ns to .25ns and no faster.  This is very sedate change to the eye and the person's brain should not see the change, but sometime the change happens faster and we see the change. like it did with the Nikon D500  A very costly camera ($5,500). Nikon fixed that change real fast with a firmware update on issued cameras and include the change in newly issued cameras.  I am not sure that this is problem is global or isolated.  That needs to be looked into.  For me I have the Phantom 4's and Mavic and none of them show the flicker I see in your video.  Wish I could help but DJI has the coding on this.... One side note editing software can also cause this change and software may affect one video and not others. That is because during the video the program of the software sees something that isn't really there.  I have had that happen a lot to me.  It is a frustrating problem because the video that the program changes is the one I may need for the production and I am screwed.  I am a software engineer and even I cannot find a fix for this type of problem except RESHOOT.  I hate that... lol 
2017-1-31
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Dennis9877
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yep this is clearly a White Balance problem see post below.  See how the color change is.  To most it is a light flicker but it is really a color change.  White Balance...  change it is to late because the video is shot already.  Should I always use temp conversions 56K or what ever???  Could.    Video shot it is to late for that video in is burned... Sorry    Are we compressig to much?  Maybe but I don't think so.  Auto system sometimes just screw things up.  That is why a  Cinematographer wouldn't use Auto settings Ever, Never ever use Auto settings.  Unless you don't care about these things happening. Sorry, but that is just the way life is.
2017-1-31
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Dennis9877
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Sorry my son said I am being snarky and should tone it down.  Sorry I will try and do better.  Please don't use auto unless you are just shooting video that really does not need sharpness and such....  If you use manneul you will not see this flicker.   Some ask what setting should I use. That depends on the lighting of the area you are flying in.  Here is a color temp posting that will help...   http://tubularinsights.com/color-temperature-video/   thru it you will see outside sunny day nice very little clouds and such 56K is great where gloomy day may need 93K... well it is really 5.3K and 9.3K  go figure. hope it helps.  Been doing movie for over 45 years now and still having fun trying new ways to mess up my videos.  lol
2017-1-31
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WindSoul
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in auto exposure is normal what you see. at low altitude the light is poor and the sensor sensitivity is up to give you detail in low light. while it gains height, the sky brightness increases the illumination and the sensor automatically decreases sensitivity in order to render detail in bright areas of the picture. obviously at the expense of dark areas which loose any detail.if you try a preset of a white balance, that will maintain the exposure and avoid the appearance of different illumination on different scenes. however, the details will be lost in either too bright or too dark areas of the picture. however, if the scene lighting changes slow enough, then the effect can be greately attenuated even in auto exposure.


Please enjoy the next post. Captain, amuze us!
2017-1-31
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Geebax
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WindSoul Posted at 2017-1-31 12:09
in auto exposure is normal what you see. at low altitude the light is poor and the sensor sensitivity is up to give you detail in low light. while it gains height, the sky brightness increases the illumination and the sensor automatically decreases sensitivity in order to render detail in bright areas of the picture. obviously at the expense of dark areas which loose any detail.if you try a preset of a white balance, that will maintain the exposure and avoid the appearance of different illumination on different scenes. however, the details will be lost in either too bright or too dark areas of the picture. however, if the scene lighting changes slow enough, then the effect can be greately attenuated even in auto exposure.

It was worked out a long time ago this is caused by using the auto white balance feature, it has nothing to do with exposure.
2017-1-31
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WindSoul
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Excellenttly said, mon capitaine!
2017-1-31
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