How do I maintain aspect ratio of images in a replicator?

The only time I've seen something like this is when the original file was saved with an aspect ratio and *non-square* pixels. Adobe applications (Photoshop is the one I know) have presets for video, like NTSC 720x480 in either 16:9 or 4:3 aspect. Taking the 16:9 as an example, what should be 854x480 pixels is saved as 720x480 and the pixel widths are set to be interpreted as 1.21 times wider. In other applications, this will appear to be about 21% squeezed when viewed as square pixels.

If this is the case, (or even *close* to the case) here's what you need to do:

In the Layers list window - at the top -- click the media tab.

Select the image/AI file.

In the Inspector, click the Media tab (again...)

Find the Pixel Aspect Ratio and select (most likely) NTSC D1/DV Anamorphic

Motion will automatically set the 1.21 aspect I was trying to explain at the top. If that doesn't work, select one of the other presets or Custom and type in your own aspect "correction" value.

HTH

What's happening is actually normal behavior because you're scaling the replicator with that control (as shown in your video). If you want to change the Size (bounds) of the replicator, you need to go into the Replicator tab and dial down the Size parameter to reveal the width and height parameters, or, you can go to the tools popup menu at the bottom of the canvas (with the replicator selected in the Layers list) and select the bottom-most tool which is the "Adjust Item" tool. You will see a different set of onscreen controls for resizing the replicator which you can drag around for visual placement.

Make sure you go into the Properties inspector and reset the Scale for the Replicator in order to reset the graphics to their original "aspect".

HTH