All media in ProPresenter supports three scaling options: Scale to Fit, Scale to Fill, and Stretch to Fill. By default, Backgrounds use Stretch to Fill and Foregrounds use Scale to Fit. You can change these two defaults in Preferences under Advanced if you would like them to use different scaling behaviors.
The easiest way to explain what each of these settings does is to simply show you. In each image, the box with the black outline represents a 16:9 screen. The ProPresenter logo is a different aspect ratio, so it isn't going to fit properly on the screen.
Scale to Fit
Scale to Fit expands the image from the center point until it hits two edges of the screen. This may result in letter boxing (bars across the top and bottom) or pillar boxing (bars on the left and right). In this sample, the image first reaches the top and bottom, resulting in pillar boxing.
Scale to Fill
Scale to Fill expands the image from the center point to fill the entire screen. If the image is a different aspect ratio, then cropping will occur on either the top and bottom or the left and right. As you can see below, the logo will be cut off on the top and bottom in order to fill the entire screen. The aspect ratio of the media is maintained.
Stretch to Fill
This option simply makes the image fit the screen with no regard to the aspect ratio. This may result in distortion of the image if it is a different aspect ratio than the screen. If your media has defined objects (people, buildings, circles, etc) that will show distortion, you may not want to use this option. For most looping backgrounds, any distortion that may occur wouldn't be noticable.
You can change the setting for any media cue in the Cue Inspector. Right-click on the media cue and select Media Properties. Once the Cue Inspector opens, click on the second tab (gear icon) and change the scale option. If you use Scale to Fit or Scale to Fill, you can change the anchor position of the media file as well.
