You don't need AE for this. In a video editing application, set an in and out point on your clip. Then place the same clip one after another in the timeline. Done!
Echo and posterize time unless the camera is moving.
First of all thanks for your answers, Dave and Rick!
But I don´t understand what you mean with "Then place the same clip one after another in the timeline", Dave?
I want to show the movement of the tennis racket, but when I place one video clip above another one, I can´t see the other one, because (understandably) only the first clip in the timeline can be seen.
Okay, I did that. But now the whole movement of the player duplicates and it is blurry.
I just want to show the arm and the tennis racket.
Maybe if I put a solid on the part of the tennis player, that I want to show?
To show just one element in a frame you'll need to do some roto. Sorry my description was incomplete. I was answering from my iPhone and assumed more familiarity with compositing. You will need 3 layers. The bottom will be the original video, the middle layer will be the object you want to echo separated from the background, the top layer will be a copy of the middle layer so the echo will appear behind the object.
Here's what I'd do if I wanted to isolate the tennis racket, or in this case, the car.
- Add your video to the timeline
- If there is any camera movement then you MUST stabilize the camera first so the background does not move and you may have a serious problem making this work
- Duplicate the video layer
- Use RotoBrush (or roto by hand or use another procedural matte technique) to isolate the car from the background on the top copy
- Freeze the RotoBrush and duplicate the layer again
- Add Posterize time to the middle layer and set it to something like 1.3 fps
- Add Echo to the second layer and set the delay to a negative value that corresponds to your frame rate (convert frames per second to seconds per frame this way: 1/1.3 = 0.76923077), set the Echo Operator to Composite in Front and adjust the Decay to get the look you want
- If you have stabilized the shot you'll now have to put the camera movement back in for the top and bottom copies of the video and apply tracking info to the middle layer to keep the duplicates lined up with the road. This will not work reliably with most hand held or panning shots.
As I said before, if you have a hand held shot you are in for a bunch of extra work and the shot may not work at all. Pulling off this kind of effect successfully requires some knowledge of the process and some careful pre-production planning.
I´m really thankful that you posted the whole workflow! That was very helpful.
But I think I need to watch a few tutorials that focus on RotoBrush first. I worked only with the pen tool before.
But I will try to understand today, how to use the RoboBrush and then go step-by-step through your solution.
Mark (and not Robin, I was lost in thought on this day)