Examining Motion characteristics p.11-3

1. Drag the Current Time Indicator (CTI) on the Time Line anywhere in the clip so you can see the video in the Program Monitor.


2. Click inside the Program Monitor screen.
That puts a bounding box with a crosshair and handles around the clip (as shown in the next figure) and activates the Motion Effect in the Effect Controls panel. 

(activation and bounding box figure)

3. Click anywhere in the clip bounding box in the Program Monitor, drag this clip around and note how the Position values in the Effect Controls panel change.

4. Drag the clip so its center is directly over the upper left corner of the screen and note the Position values in the Effect Controls panel are 0, 0 (or close to that depending on where you placed the center of the clip).
The lower right corner of the screen is 720, 480, the standard NTSC DV screen size.

Note

Premiere Pro uses something like an upside-down X/Y axis for screen location. That coordinate system is based on a methodology used in Windows for so long that to change it now would create numerous programming headaches. The upper left corner of the screen is 0, 0. X and Y values to the left and above that point respectively are negative. X and Y values to the right and below that point respectively are positive. 

5. Drag the clip completely off the screen to the left as shown in the next figure.
(figure)


6. Fine-tune that adjustment by changing the Position values in the Effect Controls panel to around -360, 240. Since 360 is half of 720, this puts the right edge of the clip at the left edge of the screen frame. 

7. Put the CTI at the beginning of the clip (press Page Up or Home). Click the Position's Toggle Animation stopwatch to apply a Position key frame there.


8. Drag the CTI to the center of the clip. Change the clip’s Position to around 360, 240 (the center of the screen).    Changing the Position parameters adds a key frame there.

9. Put the CTI at the end of the clip (press Page Down, then the left arrow key).


10. Change the clip’s position by typing the values of 360, -240 next to the Position of the Effect Controls Panel.
That puts the clip completely above the screen and adds a key frame.


11. Play the clip.

It moves smoothly on-screen, then slides off the top. You have created a path (if you don't see the path, click on Motion in the Effect Controls panel to switch on its display). Make note of a few things (highlighted in different colors in the next figure):

·         It's a curved path. Adobe Premiere Pro automatically uses Bezier curves for motion.

·         The little dots describe both the path and velocity. Dots close together represent a slower speed, dots more spread out represent a faster speed.

·         The little four-point stars are key frames. 

(figure)

12. Drag the center key frame in the Program Monitor (the four-point star/square) down and to the left. 
Notice that the dots get closer together to the left of the key frame and farther apart to the right.
 ( figure)


13. Play the clip and note that it moves slowly until the first key frame then speeds up.

Note

By moving the center key frame you changed its location and thereby the distance the clip traveled between it and its adjacent key frames. But you did not change the time between key frames. So the clip moves faster between key frames that are farther apart and slower for those nearer to each other.


14. Drag the center key frame again, this time down and to the right (use the next figure as a reference).
That creates a parabola with evenly spaced dots on both sides, meaning the velocity will be the same on both arms of the parabola.
(figure)


15. Drag the center key frame in the Effect Controls timeline first to the left, and then most of the way to the right.


16. Play this clip and note how much slower it goes at the beginning and how much faster at the end.
It should behave the same way it did when you open the Lesson 11 project


Note
Now you are changing the time between key frames but not changing their physical location in the screen. The little path/velocity dots in the Program Monitor will spread out or slide closer together but the key frames will not change locations..