Cleanplate Remove Drifiting

I’m sure I’m overlooking something obvious, but am on a deadline and hoping someone can point in the right direction.

I’m doing a remove with a clean plate, something I’ve done many times.

I have the background layer and tracked, I have a hold out matte also tracked and a remove layer (in typical stack: holdout, remove, background). Then I made a clean plate at the best place in the middle.

Everything removes perfectly on that frame. But as I’m moving to the left/right the remove result shifts. It’s not taking the motion of the background vs. the clean plate into account for some reason.

I tried linking the remove layer both to the bg track, track it on it’s own, or none. To no avail.

I’m trying to do a single clean plate over 205 frames for consistency. Or is that a case where multiple clean front and back would help. I know there are some parameters to define the search range.

It’s a person standing in an exterior location with a mostly locked shot with minor tripod drift. There is an element in the landscape behind him that needs to be removed. So the clean plate simply clones that part out and removes that in all frames. The background is pretty static, some bushes in the distance.

Thanks.
Jan

Do you have a screenshot? Do you mean the animation shifts or the plate jumps? I am trying to visualize so I can advise. Can you check the background track and make sure it is rock solid across the whole shot?

Thanks for the follow-up. Can’t do a screenshot of this.

What I meant was that the area the area the remove tool copies from the clean plate to cover up the undesirable element shifts (isn’t locked in place). There is lines in the grass that should remain in the same place of the scene, but it shifts and looks out of place. I think it’s a perspective shift that’s not compensate.

But your question about the background track is the likely issue. It looks like the background track included too much foreground that’s on the same plane. I have shifted the background shape up vertically so it only covers the trees and shrubs while tracking and then bring it down afterwards. That seems to have helped.

Jan

I think I got to the bottom of it. The background track definitely helps, but wasn’t the problem. This clip was 200+ frames long and the most logical clean plate was at the back end. Once I added a second clean plate at the front things stayed in place much better. In the end I needed a third clean plate at about the mid point. I had hoped to avoid that to not get any blending between them. But I guess the algorithm may need it to anchor where pixels belong in the frame.

Great! All of those sound like very valid solutions and I am glad you are getting better results. Thank you for letting us know your trouble shooting process. It will help other users.

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