Because they were originally shot on 35mm film, which doesn’t have a “resolution” per se, but is effectively high enough quality to produce 4K-like images. Therefore, our ability to make high quality digital copies depends on our ability to scan the original film strips into a digital format. Originally, those films were copied to VHS, and eventually DVD, which only had so much resolution, so they only made digital version of the films detailed enough to work in those formats. You can’t make a Blue-Ray quality film from an SD-DVD, you have to go back to the original film source. Some stuff made before digital video was shot on smaller film formats or tape, so recovering 4k quality digital video from them doesn’t work the same.
[Here’s a video](https://youtu.be/rVpABCxiDaU?si=gkTrSJ5hhuawQnzL) that will teach you more than you could ever want to know about this topic.
Latest Answers