system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are film studios able to take old films filmed on a film reel and digitally remaster them to look as crisp as digital video?
gpt
Film is much higher quality than any of the digital video formats in common use.

You can't really put a number on film's exact resolution, but it's ~9-10 megapixels; when you scan a 35mm negative into a computer, you keep discovering additional details until you reach 9 to 10 megapixels, so that's its rough resolution, varying a little depending on the exact brand and quality.

DVD is only 0.34 (USA/Japan) or 0.41 (Australia/Europe) megapixels. HDTV is only 0.9, and Blu-ray is only 2.1. 4K is 8.

Or in other words: if we take a film reel and use a big scanner to create a digital video from it, scanning at Blu-ray resolution only captures around 1/5th of the detail in the film. That's how they make DVDs/Blurays, they use a big scanner.

8K is the first digital video format we've created that's higher-quality than professional-quality 35mm film. It's still not better than 70mm film (the kind used for 2001: A Space Odyssey, Spartacus, Lawrence of Arabia, etc and Soviet films of the 70s and 80s).