Looking for specific effect for a scene

[i_am_legend]

Hello!

I am strugglin to find a specific effect for a piece in the making.

I have some footage of a crossing with loads of traffic, the footage is still footage primarily. What i want to do is - i want to make all things disappear except the moving cars, bicycles, people and so on.

What i have thought about is to mask everything that moves out, but i dont think i will be alive until its done.

Can someone save my life, any help and tips arer very much apreciated!

(I am using after effects but i am willing to give it a go in other softwares)

Thank you so much for your time

All the best / Luca

[Dave_LaRonde]

I'm puzzled -- if it's still footage, nothing moves.

[i_am_legend]

Sorry for the confusion

Yes it is still footage, nothing moves, only the cars, people, birds and all living. I am looking for a solution that will make all the non moving fade or transparrent.

Thanks for the quick answer man

[Dave_LaRonde · Accepted solution]

Oh -- you need to build a clean plate.  It's a little tricky, and a LOT easier if you just shoot one when you're set up.

A clean plate's an image that doesn't contain any undesired stuff in it, and it can be a real still image.  You'd build it by going through the clip, finding spots in the shot where there's nothing -- maybe a gap in traffic.  Using Time remapping to freeze the shot at those points is essential.  You mask the various desired portions of the shot, and keep layering one on top of the other.

Then save out a still frame & re-import.  Put your Motion footage on top of it and you can dissolve the top layer in & out all you  want.

[Rick Gerard]

I think Dave misunderstood your problem. You have a shot of moving traffic and a locked off camera and you want to remove everything but the traffic. This is going to require rotoscope unless there is something in the background that can be used as a procedural matte. Rotoscope may go faster if you use Rotobrush, but that tool will not work well on all shots. There is no magic button that will remove the background. If the lighting is exactly the same and you have some part of the shot that has no traffic in it you may be able to use a difference matte by picking a clean frame, but for difference matte to work well your footage needs to be uncompressed 444 color with absolutely no compression artifacts. I've tried using difference matte a couple dozen times and only had limited success.

Show us the shot and maybe we can give you some suggestions that point you to an efficient workflow but I fear that your project is just going to take a bunch of hand work and a lot of time,