IS YOUR DISC REALLY 4K ULTRAHD? | 4K MASTERED BLU-RAY VS TRUE 4K BLURAY

I’ve had a lot of comments and questions come to me via email and social media about the differences between 4K restorations on Blu-ray Discs, and true 4K UltraHD Blu-ray. Let’s talk about it and hopefully this clears things up!

Join this channel to get access to perks:

Donate to the channel:

Follow me!

Install the Lustre browser extension for easy home theater tech comparisons!

4K TVs Worth Buying:

4K Projectors Worth Buying:

Blu-ray Players Worth Buying:

My Home Theater:

Films At Home Merch Store:

Sign-up For A FREE Amazon Prime Trial:

**As stated in the video, I will earn a small commission from any purchases made through my affiliate links.**

[JeffRauseo]

Couple notes on this, because I simplified things for the purpose of the video and to not get even more confusing.

Bottom line is - BUY THE BLACK BOX THAT SAYS 4K HDR. Anything else isn’t “true 4K”, it’s just a 4K master downscale and compressed to fit on a Blu-ray Disc.

- A 100% uncompressed movie would be a monster file. Terabytes. But the 4K discs are much less compressed than Blu-ray.
- There are some differences between Blu-ray and 4K discs at a much deeper technical level. Beyond what most people need to know or care to know. So I didn’t dive deep there for the purpose of a simple explanation.
- 4K is H265 compression and Blu-ray is H264. It’s a different type of compression. Taking a 4K master goes from 8 million pixels to 2 million pixels. Basically compressing the pixels down/downscaling. To me, those are sort of interchangeable terms.
- 1080p Blu-ray players cannot read the larger disc types so that is why they can’t play 4K discs. And yes there are deeper technical differences as well.
- As far as I can tell, you can put a 4K file (if it’s small enough) on a Blu-ray disc. You’d still need a 4K player to play that back in 4K because a regular Blu-ray player won’t support it.

Hope that helps! I tried to keep it simple enough for anyone to understand, but if you want to take a deep dive there are much smarter people than myself who can really get into the nitty gritty details of the discs.

[TimTringleJr]

Correction: 4K UHD encodes are still compressed. You state more than once that on 4K it’s uncompressed which is just not true. Uncompressed video is WAY larger then the 80 or 90 GB UHD encodes, H265 is just more efficient and compresses the same quality at a much smaller file size. Which is why 4K becomes possible at only twice the space as a maxed BD disc.

[aaronlewis]

True Lies and The Abyss come on Cameron! I'm sure the filming of Avatar 12 halted filming due to covid it would have been a perfect time to look over the these movies for approval of a Blu-ray or 4k

[archiefc]

Man your videos are so thorough and helpful!! Small time collector only have about 30-40 films I really love but I am scoping out 4k TV's and more into the physical media aspect and you've helped me out so freaking much !!!

[GrilledTofu]

what would it take to get lord of the rings extended editions on 4k lolol

[zjohnson]

Just got my first atmos system and your vids kept coming up in my movie research. Subbed great content.

[herotolegend]

I was a little confused. And you cleared that up for me wonderfully. Thanks a lot man!

[LILGHETTI]

I have the 2018 blu-ray of 2001: a space odyssey which is a 4k restoration and it looks really good but not as the 4k, because it was half the price! Great informative video Jeff!

[gizmoitaliano]

I love your enthusiasm Jeff, you remind me of me back when I started collecting LaserDiscs and learning about movie restoration and video mastering.

I have to agree with some of the previous comments though, the explanation is a bit inaccurate...

1. You can't hpothetically put 4k Ultra video on a BluRay disc and play it back on a standard Bluray player, the 4K video isn't compatible with BluRay players due to incompatible: compression codec, video resolution, colour spectrum, etc.

2. While Arrow may have a 4K master of Robocop they can only decide to release it on 4k Ultra BluRay if the rights agreement they negotiated with MGM permits it, they may only have the rights to release it on Blu-Ray.

The simplest explanation is:

A movie that's been mastered in 4K on Bluray is simply a 4K master that's been downresed to 1080p for BluRay.

The studios have been using 'Mastered in 4K' on BluRay packaging as a marketing gimic, possibly trying to mislead consumers into believing they're getting a true 4K video presentation.

Assuming the same film source and the same mastering equipment are used, there would be very little difference between:
- a movie that's been downresed to 1080p from a 4k scan
Vs.
- a movie that's been scanned natively at 1080p

The main reason a Mastered in 4k BluRay looks better than a previous Mastered in 1080p BluRay is that the 4k master was created 5-10+ years after the 1080p master, using vastly improved mastering technology/techniques and they've probably maximized the movie's bitrate favoring image quality over supplemental features.
It's not a fair comparison.

[tjdw]

I was wondering your opinions on 4k streams vs a 1080p blu-day disc, are blurays a better overall picture than a 4k stream?

[aaronhinton]

"A typical 4K master is 80-90GB." Um, no. The 4K master is the file on the servers at the studios, and it's literally terabytes of data for the single movie file. Yes, terabytes. Typically films are mastered in OpenEXR, DPX, or ProResXQ. The 80-90GB version is what you'll find on a consumer disc, and it's a compressed copy of the 4K film, NOT the master.

[kthx]

A 4K restoration on 1080p blu-ray is 4K down-rezzed to 1080p--simple.

[NicholasConstanitnou]

One small thing I would add is that 4K bluray encodes onto the disc with HEVC which is a slightly more efficient compression than the standard Bluray encoding with is AAV so technically the bluray and 4K bluray discs are different sizes and using different encoding formats too. Very complex topic but think you did a good job simplifying it for the majority of people (the rest probably knew it already anyway so 😂). Keep up the great work

[daledeson]

The single most important difference between 4k and blu-ray is HDR, it's the HDR that makes the real difference

[devononair]

This was pretty enlightening for me in terms of how people were confused by this, because I had no idea people would find that confusing! Good explanation :)

[Meat_and_Potatoes]

Thanks for the vid, Jeff, I actually had been wondering this very subject.

[brucethen]

Technically all movies are compressed.

Downscaling from 4K to HD will reduce the file size on it's own and OFC you will loose resolution / detail

Also, I do not believe that a blu-ray player would be able to decode a 4K file, even if it was in the correct format

[DragonboltBlastter]

Before I buy a UHD blu ray disc. How can i know if the movie is native 2160p or upscaled?

[Kobiedog]

The need to put Robocop on 4K UHD blu ray, literally one of the greatest films ever made.

[aandrews]

When you’re in a shop and holding a movie in your hand and looking at the back of the case, how do know if it’s Native 4K or Upscaled 4K?