OBS is really the big enabler in (my) online teaching at the moment. I use an IPad with a drawing app, I draw on a predefined colored canvas and overlay it in OBS with a chromakey filter. If that is available to you, it is even cheaper. But then again, I am looking slightly down while writing..
Just the other day I was following some complicated tutorial for getting blackmagic's atem mini pro hdmi capture/mixer board to work in Wine in Ubuntu 20.04 .. I finally gave up and tried decided to play around with a webcam in obs instead. There to my surprise, OBS was listing the ATEM's capture input out of the box no wine required, with no config as a video source!
Same! I don't do anything as elaborate as the article, but I use a combination of OBS, PowerPoint, GIMP, IDEs, and a cheap Wacom tablet to demonstrate all the concepts for my classes.
The "Khan Academy"-style drawing I think really helps keep learning online casual and conversational in a way just presenting slides doesn't.
Yes! Educational research supports being casual and conversational. Although for drawing diagrams, a physical overhead with the instructor's hand visible seems to work far better than Khan style video.
See: Fiorella, L., & Mayer, R. E. (2016). Effects of observing the instructor draw diagrams on learning from multimedia messages. Journal of Educational Psychology, 108(4), 528.
Were you using Zoom? I had a lot of trouble using either the OBS virtual camera or sharing the composition window---what was transmitted was either potato quality or the video lagged very far behind.
After a LOT of debugging, I'm convinced it was due to Zoom bandwidth throttling, which I was unable to get waived.
Yes. Zoom is fine, you can either up the resolution for the "speaker view" in your account preferences (maybe just in the paid version), or even better: Use the screen share feature and under "advanced" you can share a second camera, or in this case: the virtual OBS camera. This will usually not be compressed as hard as the speaker views.
In some cases it looked fine for me but for the other persons it looked really ugly. Make sure you use the v"2nd camera mode" in screen sharing options of zoom. Do not do it as your own camera or it will look really bad. On Linux, I have to start zoom after Obs and the virtual camera for all that to work properly.