- 21 January 2007
- 21,629
http://www.audioholics.com/hdtv-formats/uhd-blu-ray-specification
...
There are currently plans for 66GB (dual layer) and 100GB (triple layer) UHD Blu-ray discs. Lord of the Rings fans rejoice, the goal with the new disc sizes is to keep movies on a single disc. The data rate for the 66GB discs will be 108mbps and the data rate for the 100GB discs will increase to 128mbps.
While many enthusiasts focus only on the resolution of UHD, there are two even more important improvements that will be coming with UHD Blu-ray.
The first benefit is color space. All HDTV sets today support the HDTV color space, which is called rec709. The problem with rec709 is that it doesn’t display either the full color spectrum that the human eye can see or the DCI color spectrum used in the theaters. In other words, HDTV sets today have a limited color space.
UHD Blu-rays are slated to support the BT.2020 color standard, which can render around 3/4 of the visible color spectrum—that’s in stark contrast to the 30% or so of the visible spectrum that the rec709 standard supports. In practical terms that means that we’re now going to be seeing better, richer, and more accurate colors via UHD Blu-ray discs. The irony in this, however, is that no HDTV today can support the wider BT.2020 standard. The Blu-ray folks are saying that they are trying to future-proof the standard, which makes lots of sense to us. The only head scratcher with UHD Blu-ray is that the color spec slated to support only 10-bit color. Using 10-bit color may end up limiting chroma sub-sampling to 4:2:0.
The second improvement is high dynamic range, abbreviated as HDR. In simple terms, HDR will improve the range between the lightest and darkest parts of a picture. Why is this important? It makes pictures look more lifelike and it’s very similar to the HDR feature on many digital cameras. So, instead of white areas being washed out or blacks being crushed, we’ll now be able to see better detail and a finer range of brights and darks. High dynamic range is one of the key elements that makes images look more true-to-life.
The third improvement is high frame rate (HFR) support up to 60fps (frames per second). The acclaimed Lord of the Rings and Hobbit director Peter Jackson has been shooting the Hobbit in 48fps and James Cameron is reported to be shooting the new Avatar movies in 60fps. The new UHD Blu-ray standard will now potentially allow home users to experience HFR movies as the director intended. Movies shot with HFR eliminate the blurring that is characteristic of traditional 24fps movies—especially during fast-moving action scenes.
...