Kaltura offers two ways you can record your presentation video. Kaltura Express Capture uses your webcam to record a “talking head” style video. The finished video can be downloaded and edited in video editing software.
The video below (3m 20s) from the University of Michigan demonstrates how to use Kaltura Express Capture. While the links that they mention will be wrong, you can access Kaltura Express Capture through Virginia Tech Canvas just as they show in the video:
The Basics | Kaltura Express Capture
If you want to capture images on your computer screen, you need to use the desktop application Kaltura Capture. For more information on how to use either tool, check out these resources: