What I know about the history of magnetic and optical media (VHS, CD, DVD, Blu-ray and so on) is that they’ve all been invented to perfectly fit data and movies.
I do not own any sort of Blu-ray device, but I know that even with 25 GiB (single layer) and 50 GiB (dual layer) the movie has to be compressed with the MPEG-2 algorithm.
So my question is:
how much space would be needed to fit an uncompressed movie ??? (where uncompressed means the same framerate, audio etc… that are shot by the camera in the movie studio).