Converting your old 4:3 movies to widescreen is easy. Just remember that you'll lose some video at the top and or bottom due to the shape of the two formats:
Here you can see the 16:9 selection area, with the extra video at the top and the bottom of the 4:3. The selection area can, of course, be moved up and down dynamically, but you will lose the video outside the area.
So, how do we accomplish this cropping? We use the Section/Zoom effect function of MEP 15.
Follow these steps:
The selection area can be dragged up and down, and made smaller by dragging the corner handles in (zooming in on the video) but it will stay in the 16:9 format/shape.
By using keyframes, the selection area can be moved about dynamically to ensure that the interesting part of the video is not lost. For example, if you wanted to see more of the roof as a balloon floated up, you'd first set a keyframe to anchor the initial slelection area position. Then, as the balloon floated up, you would move the selection area with it, using keyframes along the way to track the balloon.
The output can be viewed by clicking on the Preview button.
Here's a video tute: