system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are old movies and tv shows remastered into HD?

Event Horizon spawned this question.

Edit: I know Event Horizon isn't that old, but it's what I am currently watching.
gpt
Older movies and Event Horizon (great movie!!) qualifies, don't have a resolution because they're shot on real film so they are analogue, meaning you can digitalise it in HD no problem. You simply capture it in 1920x1080 pixels and you have yourself a full HD version.

More modern filmes shot digitally are much harder to interpolate to a higher resolution as you have to add pixels where there are no pixels.