Hello,

I noticed a strange artifact on a couple of my shots and I don't know how to correct the problem.

For example, take a look at the video below. I was filming at 4k - 30fps -1/60 shutter / ISO 100/ ND16 filter / None (profile) / Sunny balance. +1. 0. 0.

I've tried reducing the sharpness but it doesn't seem to make a difference.

Look at 40s for the flickering around the trees and right after that, when the camera pans down, you can see the image gets all grainy.

Any idea what's going on?

OK, I watched.  I don't see what you are talking about.  Are you shooting in .mov or .mp4?  Sorry.

Didnt notice anything at 40sec but at 33sec (alias over the grey triangle dome) is definitely a result of the +1 sharpening... You can also try to fly slower, in my experience the camera has trouble catching up with fast jerky movements especially at 4k and especially with sharpening +1

A couple  or three things, one, the None profile isn't actually giving you the unprocessed video you might be expecting, for that you'd want the True Color profile. None boosts green, which may be making the system work harder than normal in hiding the tilt shot's compression artifacts.

Two, you need a faster frame rate to keep up with your pans and moves, especially the aforementioned tilt shot, which is notoriously hard to compress to begin with.

Three, the graininess looked to me like oversharpening. I think you rarely need to boost sharpening on the Mavic's camera except when low light levels start causing mushiness.

Hope this helps, that's a cool location!

So roughly the way the H264 compression works is that the algorithm takes a set of spaced frames called keyframes, then interpolates the content between said keyframes. This kind of compression approach has difficulty with areas of solid or near solid color because there are not enough details to work with, so in these cases you see a sort of static or noise that doesn't move between keyframes, causing jumpiness in affected areas. The None profile boosts the saturation in green, potentially smearing detail, so you'll see the effect is more pronounced in the grassy areas.

Ex Machina Posted at 2017-7-31 17:14
So roughly the way the H264 compression works is that the algorithm takes a set of spaced frames called keyframes, then interpolates the content between said keyframes. This kind of compression approach has difficulty with areas of solid or near solid color because there are not enough details to work with, so in these cases you see a sort of static or noise that doesn't move between keyframes, causing jumpiness in affected areas. The None profile boosts the saturation in green, potentially smearing detail, so you'll see the effect is more pronounced in the grassy areas.

Wow, never knew that, particularly about the None profile.
Certainly sounds like you have nailed the problem on the head.

Jenee 2 Posted at 2017-7-31 20:33
Wow, never knew that, particularly about the None profile.
Certainly sounds like you have nailed the problem on the head.

Yeah, you'd think None would mean, well, none.

Ex Machina Posted at 2017-7-31 17:02
A couple  or three things, one, the None profile isn't actually giving you the unprocessed video you might be expecting, for that you'd want the True Color profile. None boosts green, which may be making the system work harder than normal in hiding the tilt shot's compression artifacts.

Two, you need a faster frame rate to keep up with your pans and moves, especially the aforementioned tilt shot, which is notoriously hard to compress to begin with.

Wow thanks! I didn't know the None profile wasn't actually None.

I'll try this weekend again and see how it goes.