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Need help with exposure changes during a time-lapse sequence - Mavic 2 Pro

RadioFlyerMan

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I need help understanding an apparent change in photo exposure level that is occurring during a time-lapse sequence on a Mavic 2 Pro while all camera settings were on Manual.

The situation is I captured a series of over 400 photos of a sunrise, each photo taken 2 seconds apart. There is no filter on the lens. Since I expect the lighting to significantly change during the flight, I set the camera to Manual. The photos were then processed in FCPX, on an Rec.709 timeline at 30 fps. The photos are jpgs directly out of the camera, unmodified as to exposure, color and saturation. The only modification is sequence stabilization which is a simple frame to frame transformation.

Since all camera settings were fixed, I expected that the overall lighting of the field of view would change and increase smoothly during the sunrise. The problem is that during the resulting video, there are two visible “jumps” in apparent exposure level between photos that have identical EXIF data. These “jumps” or changes absolutely ruin the video. I can understand if the camera was set to aperture or shutter priority, or if the ISO was on auto. But that was not the case.

I have isolated the specific photos before and after each change. Here is the video, and the photos with their associated EXIF data. Before and after each change in the video, I have frozen the frame.

Anyone have any ideas what's going on?

The time-lapse video:

Change 1:
Before Photo:
Change 1 - BEFORE - DJI_0603.JPG

After Photo:
Change 1 - AFTER - DJI_0604.JPG

EXIF Data:
CHANGE 1 EXIF DATA.png

Change 2:
Before Photo:
CHANGE 2 - BEFORE - DJI_0798.JPG

After Photo:
CHANGE 2 - AFTER - DJI_0799.JPG

EXIF Data:
CHANGE 2 EXIF DATA.png
 
subbed because I'm curious

Do you have the RAW photos? I wonder if the JPG creation process is introducing change that's not welcome?
 
subbed because I'm curious

Do you have the RAW photos? I wonder if the JPG creation process is introducing change that's not welcome?
I don’t have RAW versions of the photos. You have an interesting theory. The thing is why just two occurrences out of 441 shots? And once it jumps, it stays there for a few hundred photos. I’m thinking maybe my camera is on the fritz.

What bugs me is I can’t trust it. Maybe I should try a different SD card. Dunno.
 
I don’t have RAW versions of the photos. You have an interesting theory. The thing is why just two occurrences out of 441 shots? And once it jumps, it stays there for a few hundred photos. I’m thinking maybe my camera is on the fritz.

What bugs me is I can’t trust it. Maybe I should try a different SD card. Dunno.
The SD Card will have zero effect on this issue. It’s more likely the image processing causing it over which there is no control.

I’ve seen a similar issue with occasional over exposure while on manual with the exact same scene with no lighting change and just seconds apart. Following the exposure change it stays that way unless I override it or repower the aircraft. It has appeared randomly but changing from manual to auto exposure and back to manual restored repeatable exposures.

I’ve also had a similar issue shooting video when the aircraft is stationary and I get sudden overexposure.
 
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The SD Card will have zero effect on this issue. It’s more likely the image processing causing it over which there is no control.

I’ve seen a similar issue with occasional over exposure while on manual with the exact same scene with no lighting change and just seconds apart. Following the exposure change it stays that way unless I override it or repower the aircraft. It has appeared randomly but changing from manual to auto exposure and back to manual restored repeatable exposures.

I’ve also had a similar issue shooting video when the aircraft is stationary and I get sudden overexposure.
Thanks. So in other words, I have to live it.
I never had this issue with my Platinum. I might as well switch back for TL.
 
It looks like a DJI bug, possibly in the conversion from the raw sensor data to jpeg images. The workaround is to adjust the incoming shot in post to match the outgoing shot. Since you have identified the points where the problem happens, making the correction should be straightforward. The other workaround would be a very quick dissolve 3-4 frames..
 
Would it be feasible to shoot Raw+JPEG? That way if the problem reoccurs you could look at the Raw files and see if it's a camera problem or a processing problem.

(I usually shoot JPEG for timelapses because of the card capacity on my DSLR, but Raw gives me better results when I can use it.)
 
Depending on your software, a MORPH transition might hide it.
 
Depending on your software, a MORPH transition might hide it.
Radio Flyer Man:

When doing a sunrise, or sunset timelapse with the Holy Grail method (day-to-night or night-to-day) you will find a large change in the lighting, of course. I set my shutter on Auto, and shoot everything saved to RAW. In post-processing, I only use LRTimelapse. (www.LRTimelapse.com)in conjunction with LrC Lightroom classic. I use the shortest interval I can get from the drone which is 2 seconds. Always feel free to write me on personal conversation or questions. The following were shot with Mavic 2 Pro (Since sold) and the 3rd clip with a DSLR.

Here are few examples using this technique
start this one at 03:24 taken with DSLR on a tripod

Dale
 
I tried it again. The exposure was consistent this time, ranging from -7.0 to +3.0. No jumps. Maybe it's a random thing caused by unknown variables.
 
I tried it again. The exposure was consistent this time, ranging from -7.0 to +3.0. No jumps. Maybe it's a random thing caused by unknown variables.
It looks better to me now.Don't you always wish you had kept the camera running for a few minutes more to let the clouds light up? I do- I am always too impatient and shut it down prematurely.

Dale
 
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