Hi @currie_s,

While Kaltura is not an Instructure product, there are quite a few Canvas schools/institutions that use it too, mine included.  Unfortunately, this is not something you can control as a normal user.  Your Kaltura admins can set a global default in what's called the KMC for each video player though.  If you can speak to them, maybe they don't know about this option, or maybe they've chosen the config they have right now for a reason.  I can tell you that our config generally makes the screen the biggest video and put the webcam in a smaller window by default for videos created with Kaltura Capture, so it's definitely doable if this doesn't conflict with other things at your school/institution.

I hope this info helps!

-Chris