Hi,
Well, that depends on the age of the movie. Older movies usually have been filmed with chemical films whilst newer movies are been produced digitally.
So for older movies they use the existing material and remaster it digitally. The result is as good as the source and eventually better if some intelligent processing algorithms are used. With newer productions you get all the benefits of 4K/8k and HDR.
According to this list the release of The Abyss will be announced this year: https://thedigitalbits.com/columns/the-4k-uhd-release-list/4k-uhd-list-01
Cheers
Peter
