Best overall picture and sound-Copied Blu-ray to 25GB or copied 4K to 50GB?

[LloydS]

06/05/19

Does anyone have a good, sound read on this?

I copy my original Blu-rays and 4K movies to keep the originals in pristine condition.......'cause, as Woody Allen said in the movie "Annie Hall", I'm anal. But I don't really know if it's worthwhile to just buy Blu-ray originals and copy them to 25 GB Verbatim blanks, or if I get real improvement if I buy 4K originals and copy them to 50GB Verbatim blanks?

What gives the best picture and sound? I know the answer seems obvious. It would obviously seem that going the "4K to 50GB blanks" route would be best, but I don't really have a way to compare. I just have the one 75" Sony XBR television and one 4k player. So has anyone actually checked this out? I'd hate to think that I'm spending the extra money on 4K originals and 50GB blanks for no good reason.

Note: I use MakeMKV and BDRebuilder to copy the original Blu-rays to 25GB blanks. I use DVDFab to copy the original 4ks to 50GB blanks.

Thanks!

[sophisticles]

There's a lot of layers to your question and I am not sure that there even is one answer to it. A lot depends on whether or not the 4k version is of higher quality than the Blu-Ray version and while it may seem like the 4k one should naturally be the higher quality variant, there a bunch of stuff to remember:

1) Not all movies are shot in 4k, some are shot in 6k, 5k, 2.5k, 2k, a mixture of these, or something else.

2) Even if the movie is shot in 4k, it doesn't mean it's finished in 4k, many movies even if they are shot in 4k all the way through are finished in 2.5k or 2k DCI and then upscaled for the 4 distribution.

3) Even if the movie is finished in 4k, that doesn't mean there wasn't any upscaling done, even if shot in 4k and finished in 4k, the movie still needs to be cropped in order to frame a scene properly and make sure that lighting, audio and other extra pieces that do not belong in a scene are not visible.

Once you take all this onto account, as well as production choices for mood and feel made during post, it's possible for a 4k version to barely be better than the Blu-Ray release, if at all. And we haven't taken into account the quality of the encoding done to each.

This is why I usually think it's a waste of time to "backup" movies in this fashion, by re-encoding them to a lesser bit rate and one of the reasons I now prefer to simply stream a movie from a service like Netflix, Hulu, Google or similar and then rip the stream and back that up.

[Cornucopia]

My take (which agrees with sophisticles - except for the ripping of streaming services part - , but supplements):

If you have been doing a 1:1 copy, either Disc->Disc, Disc->ISO, Disc->ISO->Disc, etc. and you are keeping the size intact (aka 25GB->25GB, 50GB->50GB),
AND you have been happy with the quality so far,
AND you have noticed a quality difference between say a BD version of a film and a 4kBD version of a film, when you purchase a box set that has both to be able to compare,
AND you don't intend to do any downconversions & recompressions for "portable" copies for lite media players, but rather are only using backups (ISO or Disc) instead of your originals,
AND it doesn't break the bank to get the larger blanks,
I'd say continue doing that.

Also, particularly true and additionally supporting this, when:
You want to specifically enjoy the extended capabilities of the 4kBD - 4k, Wide Color Gamut (rec2020), HDR.

If it's anything else, you can probably compromise, though you'd have to do some A/B comparisons and evaluate yourself whether your 2nd generation version is acceptable enough for your needs.

Scott