How to add effects with iMovie 11

Change a clip's look progressively over time using iMovie's built-in effects
Modern camcorders can automatically focus, white balance and colour correct for you. As such, most of your clips will look fine and be ready to be included into a project the moment you import them. But machines being what they are, they do sometimes get it wrong, which is why iMovie's various video tools can come in so handy.

With them, you can alter the brightness, contrast and colour of any shot. You can obviously use them to also distort the image, giving it an unnatural appearance to simulate unusual weather conditions or to create that alien planet feel you were after.

Couple those changes with one of iMovie's 19 video filters and you have a broad palette to play with (you can also copy and paste those changes from one clip to others by using the Edit > Paste Adjustments commands in the menu bar; these can save you a lot of time if you want to create a special visual style for a large part of your project).

Unlike Final Cut Pro and other professional editing packages, there isn't an obvious way to gradually apply that change over time – it's a black and white clip, or it's a colour one, for instance; there's no in-between.

So what do you do if you want to play around with your image and slowly intensify the colour – like the effect in Limitless when a mind-enhancing tablet is taken? Thankfully, such an effect isn't out of the reach of iMovie. All you have to do is cut the clip in the right place, as shown below.

How to alter a clip progressively over time

1. Find and cut


Find the clip you want to alter over time and add it to your project. Skim over it with the mouse until you're over the part you'd like the change to occur. Without moving the cursor, press the Shift+Command+S keys to activate the Split Clip tool, which cuts the clip into two at that very point.

2. All change


Double-click on one part of the clip to bring up the Inspector window. Select the Video tab and make your changes. You can also make use of the Video Effect menu in the Inspector's Clip tab to add a single effect to your clip (only one can be used at a time). You can alter your modifications at any time.

03. Transition


Go to Window > Transitions to reveal the Transitions panel, bottom-right of the interface (or use the Command+4 keyboard shortcut). Locate Cross Dissolve and drag it onto the gap between the clips. To change its length, double-click on it in your project and type in a new value in the Duration field.