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AAYUSH CHOPRA| DIGITAL EFFECTS DESIGNER

Stabelizing a Handheld Camera Shot in After Effects

Stabilizing can be defined as a process where motion tracking data from a shot is registered for removing the camera motion from it. In this process an object's movement in the shot is tracked and then each frame is re-positioned accordingly to hold the picture steady. But as the frames are re-positioned in order to hold the picture steady the edge of the picture move into the frame, leaving a black margin where the picture used to be. We can solve this problem by scaling up the size of the footage in order to push out the black margin from the edges of the footage.



01          Before starting the tracking procedure always make sure to go through the footage and look for good a tracking target that stays in the frame till the end. The best Tracking Targets should have good contrast and a clearly defined shape with distinct edges that stays the same throughout the shot. We also need to make sure that our Tracking Targets are not getting obscured by another object in the scene. For improving the chances of getting a good tracking data we will increase the contrast in the shot by applying the Brightness and Contrast effect and increasing the Contrast value to 16.


02          Double click on the footage in order to open it into the 'Layer Footage' viewer and bring up the 'Tracker' controls from the 'Window' menu. Choose 'Stabilize Motion' from the Tracker Controls and check the 'Position' and 'Rotation' options in order to get two Tracking Features which will help us in storing the position and rotation data from the footage. The Tracking Features comes with two separate boxes one surrounded by another. The Inner Box is - Match Box and the Outer Box is - Search Box.


03          Now we will move these Tracking Features to a good location on the footage like a good contrasting point which remains visible in the footage with a constant shape and color for a longer duration of time. Also make sure that the two Tracking Features are having a fair distance between each other in order to make the 'Rotation' tracking parameter to track and store the data correctly. We will also increase the size of the Tracking Features in order to make them sustain the sudden shift of the pixels that might come due to the jitters of the hand held camera moment.


04          Select both the Tracking Features in the view-port while making sure that the Time Slider is on the first frame of the composition and press 'Analyze' forward. The program will step through all the frames in the footage, moving the Tracking Features in each frame to keep them locked onto the Tracking Targets. This is the data collection phase, therefore finding good tracking data is obviously a prerequisite for a good motion track.


05          Now in order to apply the Tracking Data onto the Target Layer hit 'Apply' and select 'X and Y' as the 'Apply Dimensions'. What After Effects has done to stabilize the footage is that it has moved everything around at single point which has also resulted in the loss of footage. So in order to overcome this problem we will now smooth out this tracking data and will also limit the intensity of offsetting of the footage.


06          In this step we will connect a 3D Camera to the tracking data in order to offset it in the same amount that it was previously been offset. Create a new Null object along with a new Camera and turn on the 3D Layer Switch for the video footage. Copy all the Anchor Point data, Position data as well as the Rotation data from the Video Footage and paste it onto the Anchor Point parameters, Position parameters and Rotation parameters of the Null object. And now in order to complete this step we will link our camera to the Null object which will take away the stabilization.


07          By giving a smoothing expression to the Tracking Data parameters of the null object we can now easily smooth out the jerk and reintroduce some of that tracking data to it so that the shot doesn’t have the jerky movements. Press alt and click onto the stop watch of the Anchor Point parameter and type in ‘smooth(1,5)’ which means that this expression will smooth every 1 second and 5 samples. Similarly repeat the step with Rotation parameters.


08          Now we are left with the elimination of the borders of the footage, which can be done by Scaling up the footage or applying the Motion Tile effect to the footage. Ram Preview the footage in order to see a very well stabilized shot.


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