imovie

You can add special effects to a video clip, such as adjusting the brightness or contrast, skewing the color scheme, or making the clip just black and white or sepia in color tone.

To add special effects, first select a clip in the Viewer area.

Then click on the Effects button in the button bar at the bottom of the Shelf area on the right.

In the window that appears, you'll see a box listing special effects (each of which has a blue icon).

Select a special effect you want, such as Black and White. A preview of the effect will play when you click on it so you can see how it changes the clip. Or you can click on the Preview button to see the clip with the effect play in the Monitor to the left.

If you want the effect to fade in after your clip begins to play, drag the blue button in the Effect In slider bar to the right to adjust the timing.

If you want the effect to fade out before the end of your clip, drag the blue button in the Effect Out slider bar to the left to adjust the timing.

On some clips you can adjust the intensity or other aspects of the effect using the slider bars at the bottom of the window.

To apply the special effect to the clip, click on the Apply button.

You'll also see a red line appear under the clip, with the red area moving slowly to the right. When effects are added, the affected video must be regenerated, or rendered.

This red line shows the progress of the rendering process. It may take a few moments for the rendering to complete (particularly if you selected a fancy effect for the clip, which will take a longer time to render).

When the rendering is done, you can move the Playhead to the beginning of the clip and then click on the play button to see your movie play, with the effect now applied to the clip.

You add additional effect to other clips in the same way.

To remove an effect, click on the clip that contains the effect and in the menu at the top select Edit...Clear. That will eliminate the effect and restore the clip to its original appearance.