HD quality motion picture recordings is nothing new.

[peteym5]

If you wonder how a movie going all the way back to when humans starting making movies, and it looks like it was filmed with a modern digital camera. There is a reason for that, it is called FILM. It is a chemical analog process that uses light, putting the images onto this paper thin stuff. I came across this video that explains how it works. Shows how stuff recorded onto Video Tape cannot be transferred to modern digital media and expect great results. 
 

 

[DegasElite]

Well, how can it? Film uses no scan lines. Video does. The only way to get perfect film quality on video is to eliminate the scan lines. Then, and only then, video quality would have no bounds. That, unfortunately, is years into the future.

[RickR]

Interestingly, as @atarifan95 pointed out, some film movies have absolutely terrible transfers to DVD and BluRay.  Examples are the Disney movies Cinderella and Beauty & The Beast. 

 

[peteym5]

Much of it depends on the quality of the original film or negatives. If those are lost, and only surviving version is film or video tape version, it is lost. It may be possible to enhance the video recording frame by fame to enhance the quality using software. 

There probably is no way to eliminate scan lines with video, or get away from pixels with digital video. It is better to make pixels and scan lines smaller than what people can perceive. 

[RickR]

Interestingly, with those Disney films, the VHS versions look BETTER than the digital "new" ones.  I don't think the quality of the original film had anything to do with it, as Disney probably has more than one archived film copy that has perfect detail.  I think they just messed up in their "enhancement" process.  Colors are more vibrant, but details were lost. 

I won't post links or pictures here, a simple Google search is all you need.  One example:  In the original film Beauty and the Beast, when the Beast first makes his appearance, they purposely made him dark in shadows.  It adds suspense.  In the Blu-ray, he's perfectly visible and colored.  It ruins the suspense completely and really does make a negative change to an Oscar nominated film! 

What were they thinking?