[Tig] Dolby Vision
bcfrye at earthlink.net
Tue Apr 15 06:53:02 BST 2014
Bob that's an interesting comment you made regarding the Dolby Vision demo looking washed out. Was this the public demo in the main booth area or in the private "grading suite" demo with the Baselight? I only saw the outside demo and the content I viewed was most definitely not washed out, not in the least. The blacks were solid, the near blacks had excellent shading and the overall picture level was comparable to the standard video… only the speculars were brighter than the "normal" video, which is exactly how it's supposed to look.
This was what we achieved with the PRM-4200 running in 600nit mode, when we graded specifically for that max luminance level… with Dolby Vision, the top luminance capability is moved higher up, but the blacks and near blacks and mid tones stay put. Dolby's in house colorists worked very hard to develop that technique. While I was at Dolby I saw a a lot of this content being graded up to 4000 nit peak luminance, so even though I didn't see the private Dolby demo, I have seen a lot of content graded for DV, and none of it looked as you described.
So I'm really curious what demo you're referring to…
The video and still images on the Display Central article (and essentially in any and every attempt to capture this with regular cameras) tend to blow out the mids in the Dolby VIsion, and create a washed out look… The opening frame of the video they posted to the article shows this, which is very unfortunate as it's nothing like that in person.
The industry is certainly already moving in this direction, witness all the extended range capabilities in the cameras… and ACES of course allows so much more dynamic range to be kept thought the the entire post process… Dolby Vision really works hand in hand with these developments and trends.
You're dead on re: the issues with consumer display and the cinema. The consumer TV's slated for Dolby Vision may not go much above 800 nits, which will be an improvement, but not as much as 2k or 4k nits. Making displays that can hit 2k nits and above is not an easy process, power consumption being one significant hurdle. The power requirements of Dolby's big 4,000 nit prototype is pretty high. And as you say, brightness does to varying degrees, equate to cost. I would guess that ultimately, higher brightness will become a feature that's simply absorbed into the products as another feature, similar to how many TV's are now "smart."
Current cinema technology won't translate HDR / Dolby Vision, but you can probably guess that there is significant effort on this front as well, witness the activity by all the leading cinema projection companies in the area of laser projection.
From what I've read, Dolby is well aware of the issues of translating Dolby Vision mastered content to current, legacy and future TVs that are not HDR capable, and is working on qualifying how that will all play out. Tricky stuff indeed.
Regarding OLEDs, many have artificial limits to their max luminance so as to extend the life of the OLED system (we've all heard about the differential aging of the primaries, which will also be exacerbated with higher luminance levels). As OLEDs mature in design, I'd expect this to change. Presently, in theory, they should be able to go brighter, but at the expense of lifespan. Yes, the individual dimming capability of the Dolby PRM and their various HDR prototypes enable the black level to stay at reference monitor level, while the peak luminance can approach what we have in real life experience… that's one of, if not the best attribute of that backlight technology.
It will be interesting to see how this all plays out in the coming months / years…
On Apr 14, 2014, at 8:02 PM, Bob Friesenhahn wrote:
> On Mon, 14 Apr 2014, Robert Frye wrote:
>> Variety ran an article prior to NAB about Dolby Vision (Dolby's HDR format), and how FilmLight will be introducing support for Dolby Vision in it's BaseLight products at NAB 2014.
>> This follows on the heels of CES where it was announced that Vizio, Sharp and TCL will introduce TV's with Dolby Vision support. And now today Display Central ran an article discussing Dolby's presentation of Dolby Vision at NAB
> It was claimed that the APL of Dolby Vision content was the same as standard content yet in the side-by-side demo video, the Dolby Vision content clearly had a much higher APL (as displayed) and much of the image was washed out while the standard video looked fine. This is not the effect that I expect to see from HDR.
> While it is certainly good to master in a format which stands up well into the future, it seems unlikely that consumer equipment is going to be able to present it well and the cinemas will not be able to deliver the brightness levels necessary to produce it properly either. A brighter picture costs a lot more money.
> It is interesting that while OLED is expected to be the new big thing for this next year, it is said to not be able to produce enough brightness to present Dolby Vision properly. Perhaps only LED-backlit displays with a very large number of individually addressable LEDs would be able to produce very high brightness highlights which do not distort the image.
> While Dolby Vision seems very interesting, is it affordable for the 99 percenters?
> Bob Friesenhahn
> bfriesen at simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
> GraphicsMagick Maintainer, http://www.GraphicsMagick.org/
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