Hi there,

The "Image size and position" dialog is probably the easiest and quickest way to accomplish this effect. Here's a quick how-to: Let's assume you created your movie and the actual video footage is in track #1, possibly with the audio being in track #2. Now, you want to cover up part of the video. Make sure you're operating in timeline view for all of this. Import your cover-up image (e.g. a black still image or some kind of logo or pattern) into a track with a higher number (e.g. track #3), parallel to your video. Use the start and end handle of the still picture to extend it over the entire duration of the video in track #1. This will result in this image having a higher priority and being displayed in front of the actual video footage. By default, the image will be stretched to fill the entire screen and will completely cover up the video. So, this means we're not done yet. In the next step, you would right-click on the track with the cover-up image and bring up the "Image size and position" dialog from the context menu. In this dialog you can use the orange handles to manipulate the size and position of your cover-up image in the preview monitor. You will probably have to take off the tick in the "Keep proportions" checkbox to achieve the desired size. You can scale and move the image to only cover the bottom part of the screen, so the video footage below becomes visible again. Confirm the "Image size and position" dialog. Done.

I suppose, if you really just wanted solid black color to hide the undesired bottom third of the video, you could also further simplify this procedure: Instead of importing a cover-up image into your arrangement, you could just bring up the "Image size and position" dialog for the video footage track itself. Then switch to the "Cropping size/position" mode and move up the bottom center orange handle until the entire undesired lower part is no longer visible.

I hope this helps! Feel free to ask if you have further questions regarding this procedure.