I can see that some 4K movies take up a lot of space, up to 70GB each, this is ONLY the movie without extra material etc.
However, it makes me wonder if you can even see a difference between them vs compressed x265 4k, or 1080p when you sit 3-4 meters from a 55" TV.
Personally, I have a 55" TV and sit about 4 meters from it. I have no sound system, so therefore I don’t need DTS or TRUE HD soundtracks either.
Mostly I download RARBG or PSA releases in 1080p. They take up between 1.5GB and 3GB each and play fine via Plex and actually look OK.
What do you get most of 1080p, x265 2160p or REMUX 4k?
There is a difference between being able to tell the difference yourself, and there being one to start with.
For some, yes. For others, no. Depends entirely on the content. There are some old movies, released on bluray, heavily grained, lots of dark scenes. In these, you tend to notice the compression quickly, mostly because reducing the size of such media is tricky, with the grain and gradients.
Then there are others, simpler type of movies. Think, simpsons, or any cartoon really. Vibrant blobs of solid colors. These compress very well, and chances are you’d be able to reduce the filesize with a much less noticeable loss of quality. On average, that is.
I normally go for remux on movies, preferably 4k and HDR. And reasonable 265 encodes for tv shows.
Best way is to compare yourself, there is no one size fits all in this case. Some might view most of their media on a tablet. Others in a home cinema with a setup that costs more than a house. Different needs, different place, different eyes.
Other than that, I prefer a remux so I can make my own encode if I feel like its worth it, sometimes it is and othertimes it’s not. I generally aim for a ~half remux size when I do. So 15-25GB per movie. Not accounting for audio tracks.
Some come with 20 lossless audiotracks, which can easily chug 15GB just in excess audio.
I provided an example, to see if you can spot it yourself, to demonstrate how important or not it is for you. This using the Avatar(2009) collectors edition remux, starting at 34.5GB.
https://slow.pics/c/C70qjAoy
There are 6 versions, navigate with the menu at the top left, or arrowkeys on a keyboard, you can also use the number keys to swap between versions.
original: ~34.5GBGB
crf 15.4: ~32GB
crf 17.4: ~22.8GB
crf 19.4: ~15.8GB
crf 21.4: ~10.6GB
crf 23.4: ~7.1GB
Personally, I notice the loss at crf17.4 and it becomes progressively worse. The smaller versions, 7-10GB definitely has significant losses, fine detail all but gone, some aspects even changed drastically (hair no longer strands in some areas, just blurs, fine lines mushy and fused together etc.)
The question is, does it warrant fives times the size when comparing the smallest (7GB) vs the original (34.5GB)? Eh, probably not. But it most definitely is a noticeable difference. I don’t think I would have gone any further than crf 17.4 in this case. Which would at least be a small reduction in size but still retaining most details.