Why movies have black bars - video essay

Last week I found myself wondering why movies have black bars. Why were they put there in the first place, and why do we still use them? I did some research and found some really interesting answers, so here's my final conclusion in the form of a little video essay!

Here's a video in which I take a bunch of comments viewers have left on my channel and reply to them.
Vlog with Ringgot?
Does finding a stick make you rich?
Find out by watching this video:

How to edit an object out of an image

Wow... I haven't posted on here in a while...

This is a video in which I show how to make an object  in a shot appear as if it was never there to start with. You can use this if you left a piece of film equipment in the background, or if a pedestrian strolls through your post-apocalyptic setting.

At the end of the video, I show how to create an advanced version of this effect using Mocha.
But I did it wrong :O
So here's a video showing how to do it the right way:
https://www.youtube.com/watch?v=IaH9YHY4aEo