Cloud shadows only moving every 8 frames

[Japie.G]

What is this? Today a very windy day with fat moving clouds. The cloud shadows are stuttering while the rest of the video is smooth. Sensor limitation?

 

[Bunny Too]

What is this? Today a very windy day with fat moving clouds. The cloud shadows are stuttering while the rest of the video is smooth. Sensor limitation?

That is the H.264 compression that only updates the entire picture every eight frames, you can take it out in post production.

 

[JTS]

Interesting. I've had a similar problem (although I no longer have the video). My one was a water tower on the horizon which didn't move smoothly during a pan but skipped intermittently, giving the illusion that it was not fixed to the ground. I put it down to some weird compression issue.

 

[JTS]

How do you take it out? Blur adjacent frames?

 

[Bunny Too]

How do you take it out? Blur adjacent frames?

There is an excellent video out there that explains how to take the stepped motion out of H.264 compression but it is beyond my scope to explain, I recommend doing a youtube search.
Regards,
-d

 

[Japie.G]

that sounds great. I can however not find how to fix that. Perhaps I am using the wrong terms for searching

 

[Bunny Too]

that sounds great. I can however not find how to fix that. Perhaps I am using the wrong terms for searching

I will try to find the link and post it here.

 

[Dragonfly1]

I found this:

 

[Japie.G]

Thanks Bunny Too!

Problem is I get this footage straight out of the mavic like this

Got it!

 

[Lamplighter55]

Have posted a similar request/quest for this issue over on the H264 thread. However all the answers given are for high frequency artefacts and no one has yet got an answer to this low contrast intra-frame stepping problem. Here's a short cropped section that I shot as 4K 24fps D-log +1,0,0 (sharpness) and AUTO ISO. So far as best I can tell it is only specific types of captures where this is happening - both in the above footage and my cropped example we are doing a slow pan (yaw). My current thinking is in order circumvent this temporal compression fudge, is to try and add overall frame noise purposefully using a high ISO and a heavy ND filter (32). Currently waiting from a set of NDs in the post, but will test when I have them - and update on any conclusions.

4K cropped example footage:-
Dropbox - Mavic_Dlog_test_4Kcrop.mp4

 

[Cliff_622]

Actually, "adding" a very light "film grain" plugin into any Mavic Pro video will help dither out noise and add a much more pleasing shadow area. Unfortunately, the Mavic Pro image noise reduction algorithm clamps down harder and harder on anything under middle grey. It's a very crude AND highly aggressive noise reduction. The further and object goes down the scopes. (gets darker) the more that it crushed by the noise reduction. I cant imagine who at Ambarella decided this was a good idea!

 

[Robert Granata]

Probably the same person who decided that auto-exposure should jump from 100 iso to 200 iso at 1/120 shutter speed when there is alot of 100 iso left.

 

[swoermck]

Recently I've also notice the stuttering of cloud shadows in my video (never really noticed it before). Any camera settings to reduce this effect? ND lense? .. or the simple solution: better fly on sunny days with no clouds ;-)

Is there a plugin for Davinci Resolve to remove this in post?

thanks,

Stefan

 

[Lamplighter55]

Recently I've also notice the stuttering of cloud shadows in my video (never really noticed it before). Any camera settings to reduce this effect? ND lense? .. or the simple solution: better fly on sunny days with no clouds ;-)

Is there a plugin for Davinci Resolve to remove this in post?

thanks,

Stefan

Having a slow shutter speed helps - as does a brightly lit day - and using an ND filter 8 and above.

 

[Cliff_622]

This is a well known Ambarella A9 image processor problem. We first started seeing this on teh GoPro Hero 3. (yeah,..that Mavic Pro's A9 image processor is THAT old)

Part of this problem is outlined in this video. It's the terrible temporal noise reduction that the A9 chip is doing. The darker a portion of the image gets, that harder it gets slammed with heavy amounts of bad noise reduction.

See this video: