4K Projectors and HDR - Page 2 - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 25Likes
Reply
 
Thread Tools
post #31 of 80 Old 09-05-2015, 05:36 PM
AVS Forum Addicted Member
 
Mike Garrett's Avatar
 
Join Date: Sep 2011
Posts: 25,391
Mentioned: 232 Post(s)
Tagged: 0 Thread(s)
Quoted: 11706 Post(s)
Liked: 9253
Send a message via Skype™ to Mike Garrett
Quote:
Originally Posted by Wilt View Post
Am I correct in saying, if you want the best HDR experience you need to view it on a flat panel?
Yes, HDR will have more range with a flat panel, but you are giving up too much size with most flat panels, to be able to rate the viewing experience as a whole, better on a flat panel.
mbw23air likes this.
Mike Garrett is offline  
Sponsored Links
Advertisement
 
post #32 of 80 Old 09-05-2015, 06:29 PM
 
Seegs108's Avatar
 
Join Date: Jul 2007
Location: Upstate New York
Posts: 10,827
Mentioned: 48 Post(s)
Tagged: 0 Thread(s)
Quoted: 5167 Post(s)
Liked: 2593
Quote:
Originally Posted by Mike Garrett View Post
Yes, HDR will have more range with a flat panel, but you are giving up too much size with most flat panels, to be able to rate the viewing experience as a whole, better on a flat panel.
This is a good point. I still want to see what HDR looks like, especially when it's done well. I'm just curious if HDR is going to be one of those defining enhancements that really puts flat panels ahead in PQ. Or if the lite-version we're probably going to get in projection bridges the gap enough where the size advantage is still an overwhelming reason to go front projection over flat panel.
Seegs108 is offline  
post #33 of 80 Old 09-06-2015, 07:24 PM
LJG
AVS Forum Special Member
 
LJG's Avatar
 
Join Date: Jun 2000
Location: Brookville, NY
Posts: 4,952
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 699 Post(s)
Liked: 407
So what would the consensus be for the minimum Native on/off for effective HDR?
LJG is offline  
Sponsored Links
Advertisement
 
post #34 of 80 Old 09-07-2015, 10:37 AM
 
RLBURNSIDE's Avatar
 
Join Date: Jan 2007
Posts: 3,901
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 2012 Post(s)
Liked: 1406
4k HDR flat panel vs 2k SDR projector at 6x the size, I would say it's a tough call which I would choose, even if prices were the exact same, which they aren't.

Sony going with HDR this year is a very good sign, although it's a shame they didn't add P3 color space support too. Not to mention their irresponsible lack of self-awareness that nobody wants to spend 5-10k for something that doesn't have proper 18bgps HDMI 2.0a chips, or if it does, doesn't advertise that fact properly.
RLBURNSIDE is offline  
post #35 of 80 Old 09-07-2015, 12:10 PM
AVS Forum Addicted Member
 
stanger89's Avatar
 
Join Date: Nov 2002
Location: Marion, IA
Posts: 23,130
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 4156 Post(s)
Liked: 2384
Quote:
Originally Posted by RLBURNSIDE View Post
4k HDR flat panel vs 2k SDR projector at 6x the size, I would say it's a tough call which I would choose, even if prices were the exact same, which they aren't.
I think it's all going to come down to how much of a difference there really is. I mean I just can't imagine going to a 16:9 flat panel from my 2.39:1 CIH setup. I mean my screen is, near as makes no difference, wall to wall. You just can't get that experience with flat panels. And if HDR isn't a big difference for existing content, if it's more a better transfer function than a different experience, well then maybe the decision would be easy.

Of course there's the additional issue that my HT is in the basement, only accessible by stairway. Now there's no corners, but there's a limit to just how big of a display I can get down there. I built my screen frame in my HT, I honestly have no idea if I could get it out in one piece.




On another topic, has anyone talked to the projector manufacturers about how HDR is calibrated? Do projectors measure, or allow entry of a measurement of peak white level? For instance can someone with a small and/or high gain screen input that their peak white level is high and thus get more headroom for highlights than someone pushing things with a large, low-gain screen?
stanger89 is offline  
post #36 of 80 Old 09-07-2015, 03:34 PM
AVS Forum Addicted Member
 
DavidHir's Avatar
 
Join Date: Dec 2004
Posts: 14,251
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 2520 Post(s)
Liked: 2196
Quote:
Originally Posted by Mike Garrett View Post
Yes, HDR will have more range with a flat panel, but you are giving up too much size with most flat panels, to be able to rate the viewing experience as a whole, better on a flat panel.

Not to mention that a good projector set-up gives a more natural, film-like look for fans of film.
DavidHir is offline  
post #37 of 80 Old 09-08-2015, 12:47 PM
Senior Member
 
LumenChip's Avatar
 
Join Date: Mar 2015
Location: Canada
Posts: 366
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 222 Post(s)
Liked: 123
Quote:
Originally Posted by stanger89 View Post
Depends on how you look at it. Take a look at the Dolby documentation, according to them, a "Standard TV Signal" (which I interpret to mean mastered to Rec 709 specs) expects a white level of 100 nits and a black level of about 0.02 nits (see page 4 of the link). Simple math shows us that that content is expected to have a dynamic range equivalent to about 5000:1. This is roughly in line with DCI specs (which require a minimum 2000:1).

Current JVCs can easily achieve ten times that today, almost one hundred times that with a their DI. On that same page, Dolby shows 2016 Dolby Vision TVs (HDR) will support 1000nit peak white and about 0.002nit black, which is a 500,000:1 dynamic range. Now that's a bit beyond the 350,000:1 that a JVC can really pull of, but not significantly so.

Going by the specs and the industry standards, if JVC (for example) can increase their brightness a bit, get it up to the 30fL of HDR in commercial cinemas, I think they've got a good story to sit on for supporting HDR.

Regarding Christie, they've got a slightly different problem a DLP chip is, in it's best (and most dim) configuration, good for just barely over that 5000:1. Unless TI has some magic up their sleeves, you have to do something drastic with a DLP design for HDR, like stacked chips, to take that 2000:1 up to 4,000,000:1.



While I understand and agree with the sentiment that implementing HDR without increasing contrast isn't a free lunch, I think it's somewhat narrow minded to call it a gimmick. HDR, SMPTE 2084 is an entirely new way of mastering, recording, and transmitting content. The PQ EOTF is a much better, more efficient way of conveying imageing information, and the metadata features will allow displays to not only know if their setup/capabilities are different than the mastering monitors, but how different, and to intelligently handle those differences.

I'm very curious to see how this all plays out. If you read about the DCI projectors at all, you find that their image quality surpasses what you would expect/assume given their comparatively "pathetic" contrast. I believe I remember reading that a potentially large part of that is the completely different transfer function used and colorspace used. I'm hopeful some of that will make it to us through WCG and "HDR" EOTF.

Forgive my delayed response. The link provided is informative and gives some usefull background into HDR that everyone posting should take a look at.


I remember watching "Transformer age of extinction" and after barely winning the fight of his life with a Hybrid, Optimus-Prime commented that he sensed the presence of Megatron in the Hybrid; similarly while reading the Dolby white paper I sensed the need for Dolby to develop performance envelops that can only be achieved for the most part by liscensing Dolby's Full Array local dimming technology.


Looking at the flower sample the brightness variation that is used in the presentation is an indication that Dolby is expecting an intrascene contrast measuring in the tens of thousands and HDR contrast topping out in the the hundreds of thousands. The JVC's contrast is a full on/off ratio but will not come close to delivering the intrascene contrast that is necessary for a true HDR image, at least not with the current platform.


However, the LCOS camp could take the Christie route and add a second reflective chip in the light path and use that chip for executing some local dimming (Dolby Vision) algorithims, now even at 100nits peak, I bet that such a projector in a dark room would decimate the best HDR flat panels. One projector to rule them all comes to mind .
LumenChip is offline  
post #38 of 80 Old 09-08-2015, 04:25 PM
AVS Forum Addicted Member
 
darinp2's Avatar
 
Join Date: Sep 2003
Location: Seattle, WA
Posts: 23,188
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1135 Post(s)
Liked: 1767
I'm really starting to wonder about HDR with projectors. If Dolby Vision has their reference white levels at about DCI levels for non-HDR content and their peak whites at 100 nits, then there is only about a 2x multiplier between peak whites and reference white. I'm expecting a much higher multiplier than that from 1000 nit flat panels, but haven't seen the specs for reference white with peak white at 1000 nits.

Given that our vision is largely logarithmic 2x luminance is not all that much. As an example, with 2.2 gamma 2x is about the ratio from 100% video level to 73% video level. There is a difference between those of course, but not an in-your-face kind of difference. On a gray ramp that is only about 1/4th of the way from white to black.

I posted this on the 20k forum about some of the big projectors with pretty limited on/off CR, but this applies to varying degrees to projectors with higher on/off CRs too.
Quote:
Originally Posted by darinp2 View Post
If you want the highlights in HDR to go up to 4x as bright as reference white the range from reference white to black is now 1/4th as big, unless some dynamic system is used, and we know those can only get things so far. Pump the ratio from peak HDR white (not sure what they call that) to reference white higher or lower and the ratio from reference white to black changes accordingly.

This isn't even taking into account that for HDR if you want your brightest white to be brighter you may have to open an iris and get less native on/off CR.

Don't take these numbers to the bank as they are just an example of what I think could possibly happen, but let's say we take a system that has 4k:1 on/off CR with the following reference white and black:

Reference white: 50 nits
Absolute black: 0.0125 nits
Reference white / Absolute black: 4k:1

and open an iris up for HDR at higher peak white with lowered reference white to make sure the HDR highlights actually show through to some degree. I could see getting something like this if opening the iris decreases the native on/off CR to 2k:1:

Peak HDR white: 100 nits
Reference white: 25 nits
Absolute black: 0.05 nits
Reference white / Absolute black: 500:1

or:

Peak HDR white: 100 nits
Reference white: 50 nits
Absolute black: 0.05 nits
Reference white / Absolute black: 1000:1

The highlights might help bias your eye and take away some of the issue, but currently I have some concern about what trying to do HDR with projectors without high native on/off CR and/or zones will mean for scenes without any bright HDR pixels in them.

I still want to see some of this stuff in action with consumers products, but am thinking more and more about the possible advantages of flat panels (OLED or LCD with lots of zones) with HDR content, although image size is of course an issue.
As Donald pointed out there, even with HDR some things could be done to maintain 4k:1 on/off CR in this case. Then if somebody wants HDR highlights at 4x reference white they could get something like:

Peak HDR white: 100 nits
Reference white: 25 nits
Absolute black: 0.05 nits
Reference white / Absolute black: 1000:1

For a projector with 8000:1 native on/off CR these example CRs could basically be doubled.

For those excited about HDR with projectors for the highlights (not the deeper blacks the zone system Dolby has provides), how much brighter do you think you will set your peak whites than your reference whites, if the projector allows the user to control this?

--Darin

This is the AV Science Forum. Please don't be gullible and please do remember the saying, "Fool me once, shame on you. Fool me twice, shame on me."

Last edited by darinp2; 09-08-2015 at 04:28 PM.
darinp2 is offline  
post #39 of 80 Old 09-09-2015, 12:33 AM
AVS Forum Special Member
 
Manni01's Avatar
 
Join Date: Sep 2008
Posts: 8,990
Mentioned: 307 Post(s)
Tagged: 0 Thread(s)
Quoted: 5345 Post(s)
Liked: 5383
Quote:
Originally Posted by darinp2 View Post
I'm really starting to wonder about HDR with projectors. If Dolby Vision has their reference white levels at about DCI levels for non-HDR content and their peak whites at 100 nits, then there is only about a 2x multiplier between peak whites and reference white. I'm expecting a much higher multiplier than that from 1000 nit flat panels, but haven't seen the specs for reference white with peak white at 1000 nits.

Given that our vision is largely logarithmic 2x luminance is not all that much. As an example, with 2.2 gamma 2x is about the ratio from 100% video level to 73% video level. There is a difference between those of course, but not an in-your-face kind of difference. On a gray ramp that is only about 1/4th of the way from white to black.

I posted this on the 20k forum about some of the big projectors with pretty limited on/off CR, but this applies to varying degrees to projectors with higher on/off CRs too.
As Donald pointed out there, even with HDR some things could be done to maintain 4k:1 on/off CR in this case. Then if somebody wants HDR highlights at 4x reference white they could get something like:

Peak HDR white: 100 nits
Reference white: 25 nits
Absolute black: 0.05 nits
Reference white / Absolute black: 1000:1

For a projector with 8000:1 native on/off CR these example CRs could basically be doubled.

For those excited about HDR with projectors for the highlights (not the deeper blacks the zone system Dolby has provides), how much brighter do you think you will set your peak whites than your reference whites, if the projector allows the user to control this?

--Darin
Darin FYI in cinemas HDR is 50cd/m2 (14fL) reference white and 100cd/m2 (28fL) peak white.

So the same doubling between ref and peak.

In a dedicated room, the difference between 50 and 100 cd/m2 is not night and day, but is very visible. Not so much as in a living room with ambient light, which is why UHD bluray is mastered with a peak of 1000cd/m2 (which happens to be the current limit of most panels) and not with the cinema range of 50-100cd/m2, which would be much better for projector owners.

JVC have announced a peak brightness for the brightest projector in their new range (X9000 with 1900 lumens) as capable of reaching a peak of 150cd/m2 on a 100" diag screen with a nominal gain. While this won't be reachable with the deepest blacks as well, it will likely yield a native on/off contrast of at least 30000:1 (iris fully open) for peak white (not sure where reference white will be in this example as it depends on each projector manufacturer's implementation), and perceptually the higher brightness will make the raised blacks more acceptable most of the time.

PQ gamma also helps a lot to resolve the shadow details and highlights better than conventional curves which had no standard set in for the consumer medium itself. Post prod houses could use anything from 2.2 to 2.5 power curve or more recently BT1886 with bluray, and consumers had a great time trying to find the correct curve for playback, although it more or less standardized to BT1886 over the recent years. None of this on UHD Bluray: PQ gamma (TS2084) is the only curve that's going to get used to master UHD Bluray content, which should help a lot to get a faithful reproduction at home.

Those having seen HDR in cinemas agree that when done well (Pixels, Tomorroland) it's a significant improvement compared to the same film in SDR. Scott Wilkinson has posted a few reviews which point at an improvement both in black levels and in highlights.

There are two major differences though between the cinemas and projectors at home:

1) cinema content is mastered for 50 reference / 100 peak white, while UHD Bluray mandatory layer is mastered with 1000 cd/m2 peak white. How the 0-1000 range will be mapped to the 0-100 or 0-200 for projectors is another issue. I don't think setting refererence white to 25cd/m2 is a solution because that would be privileging the highlights at the cost of a very dim reference picture.

2) cinemas have had historically very poor black levels and on/off contrast compared to what we've had at home with consumer projectors, so it may be that HDR in cinemas is simply partly catching up with home in that regard, so would lead to a more drastically different experience comparing SDR and HDR in cinemas than comparing SDR and HDR at home (with projectors).

So to answer your question, provided the conversion from the 1000cd/m2 peak mastered on UHD Bluray is done well, I expect HDR on projectors with a peak white anywhere between 150 and 200cd/m2 to give good perceptual results in a dedicated (fully light controlled) room. In a living room with even a bit of ambient light, I expect it might help a bit with highlights but of course not as much as panels, and the dynamic range itself will be gone of course.

However, I'm not expecting from projector HDR a significantly better experience than what we get in SDR today. As long as it's not worse (ie as long as we get low enough in the dark, that reference white is around 50cd/m2 and that the brightness reserve is used for highlights), it should be interesting, but if it leads to a loss of brightness at reference white or to raised black levels due to the lowering of on/off, then some - especially those with large screen) will likely get a better dynamic range and experience in SDR than in HDR.

For example, if you have to fully open the iris of a JVC to reach an acceptable brightness (say 14fL) for reference white in SRD, the HDR experience might be significantly worse than the SDR experience, because reference white in HDR will drop, therefore making the picture looking dimmer in HDR than in SDR most of the time. On/off contrast at peak white might be the same, but on/off at reference white will drop as well, which is why given the risk of DI artifacts you already pointed at in another thread starting with the max possible native on/off will help to achieve good results.This gets even worse if you want to support P3 as it usually comes at a brightness cost of at least 25% in current solutions (Epson LS1000 or JVC X7000/X9000) and up to 40% with the Sony VW1x00ES.

If, on the other hand, you can set your projector - in a fully light controlled room - so that your reference white is the same as what you get with bluray content, then I expect the HDR experience with peak bright highlights shooting over that to be perceptually better despite the raised black levels, at least when the content makes use of that (ie not the darkest content with no or little highlights).

This is why it's so important to integrate the way HDR works before taking at face value the increase of peak brightness (uncalibrated) in the new Sony and JVC projectors and choosing a screen size/gain for example, solely based on the SDR/rec-709 specs, unless P3/HDR support isn't a concern of course. Otherwise there is a strong risk with projectors that P3/HDR picture with UHD Bluray will look worse overall (dimmer, with less dynamic range) than the HD/SDR picture. Calibration to P3/D65 will cause at least a 50% drop from the specs (more if using low lamp) and HDR will cause reference white to drop further than that or there won't be any room for highlights, so no apparent benefit from HDR.

I might have got this all wrong so I'd love to get my expectations corrected if that was the case
mark haflich likes this.

Last edited by Manni01; 09-09-2015 at 12:51 AM.
Manni01 is offline  
post #40 of 80 Old 09-09-2015, 06:01 AM
AVS Forum Addicted Member
 
mark haflich's Avatar
 
Join Date: Dec 2000
Location: Venice, Florida, USA
Posts: 21,464
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 1418 Post(s)
Liked: 1014
I have been giving this quite a bit of thought while abstaining from posting because of a variety of factors and for what it is worth you have reached the same conclusions about HDR and various display technologies that I have. As far as front projectors are concerned, users will have to suffer drastically reduced reference white levels if they are to experience even 1 f stop of brightness above reference. And its all about where the reference white level is set to enable a target peak white including the percentage area set for the target. I suspect the situation will be much like viewing 3D. 3D is a lot dimmer reference white level wise than 2D. It has to be. Dim! Likewise this will have to be the case to give a high range above reference. Remember only new movies will have HDR but of course some digital captures will be remastered. So for non HDR source material you will go to a preset for normal HD and get todays ref white values. For HDR sources, the more or greater HDR you want, the lower the ref white level will have to be. Assuming we get a choice to specify it at the projector and that information can be communicated to whatever processes the meta data. That likely will not be the case. It becomes to complex for the market and providing it for the small segment of experts out there would not be cost beneficial.

Last edited by mark haflich; 09-09-2015 at 04:44 PM.
mark haflich is offline  
post #41 of 80 Old 09-10-2015, 12:29 PM
Senior Member
 
LumenChip's Avatar
 
Join Date: Mar 2015
Location: Canada
Posts: 366
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 222 Post(s)
Liked: 123
In summary, it seems that a 150cd/m2 projector will need some heavy handed approach to screen size/gain selection and dynamic range calibraton to reap some benefit of sorts from a good HDR source. Again, this seem to suggest that the current projector platforms are showing their age and a new platform will be needed to exract the full PQ from a quality HDR transfer, though the current crop of HDR 'compatible' projectors will see some PQ improvement.


Also keep in mind that with enough zones, Dolby Vision's local dimming technology will be modulating the greyscale in real time and is more than just a contrast enhancing tool, the highlights will definately see tangible benefits with a high lumen light engine without affecting absolute black, though high contrast projectors such as the JVC's will be able to pull this off with less zones than a DLP or LCD implementation.


Here is an idea that I would like to throw out to the LCOS camp, replace the lamp with a high lumen laser source (say 3000 lumens), replace the current RGB filters with RGB LCD panels and use the current LCOS chips for modulating the light output.
LumenChip is offline  
post #42 of 80 Old 09-10-2015, 01:21 PM
AVS Forum Addicted Member
 
R Harkness's Avatar
 
Join Date: May 2001
Location: Toronto, Ontario, Canada
Posts: 15,120
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 2753 Post(s)
Liked: 2655
Manni and Mark,

Those are pretty dour assessments of HDR on Projection. And one of the AVForum staff reported that JVC said the projector would automatically select the gamma, etc, mode when it detects HDR, which suggests efforts by the user to get around this issue will be futile (?)

On the other hand, on the side of optimism: Those who saw Sony and JVC Projection HDR vs SD demos at CES have not reported any such disappointments with a dimmer looking image. Particularly with the JVC the image apparently looked somewhat more punchy in HDR mode. So perhaps there is something missing in your assessments?

I suppose where this optimism from the show demos could be deflated is this: If the HDR coding of the material used for those demos was different and tailored for display on those projectors (JVC commissioned that HDR footage specially). If Sony/JVC were using entirely different coding than what we'll see from, for instance, UHD Blu-Ray, then I suppose UHD Blu-Ray images still carry the dimming risks you are talking about?

(But then, would Sony really have used an entirely different UHD encoding for their presentation of Blacklist and Spiderman 2 than the official specs to be used for delivery of such content?)
R Harkness is offline  
post #43 of 80 Old 09-10-2015, 01:51 PM
AVS Forum Special Member
 
Manni01's Avatar
 
Join Date: Sep 2008
Posts: 8,990
Mentioned: 307 Post(s)
Tagged: 0 Thread(s)
Quoted: 5345 Post(s)
Liked: 5383
Quote:
Originally Posted by R Harkness View Post
Manni and Mark,

Those are pretty dour assessments of HDR on Projection. And one of the AVForum staff reported that JVC said the projector would automatically select the gamma, etc, mode when it detects HDR, which suggests efforts by the user to get around this issue will be futile (?)

On the other hand, on the side of optimism: Those who saw Sony and JVC Projection HDR vs SD demos at CES have not reported any such disappointments with a dimmer looking image. Particularly with the JVC the image apparently looked somewhat more punchy in HDR mode. So perhaps there is something missing in your assessments?

I suppose where this optimism from the show demos could be deflated is this: If the HDR coding of the material used for those demos was different and tailored for display on those projectors (JVC commissioned that HDR footage specially). If Sony/JVC were using entirely different coding than what we'll see from, for instance, UHD Blu-Ray, then I suppose UHD Blu-Ray images still carry the dimming risks you are talking about?

(But then, would Sony really have used an entirely different UHD encoding for their presentation of Blacklist and Spiderman 2 than the official specs to be used for delivery of such content?)
I didn't mean to be depressing. I think it entirely depends on the setup (screen size, screen gain, etc). In the right setup, with the right content, I expect HDR to look great even with a limited range to play with, as long as we're talking fully dedicated room. Not a night and day difference like with panels, but visible. With the wrong setup (too large a screen, not enough gain) I expect it to look let's say disappointing compared to SDR well done in the same setup. Basically if you don't have any reserve of brightness (say you need iris fully open in SDR to get reference white to 14fL) I don't see how HDR could be better, instead it will look dimmer and less contrasty at reference white.

This is exactly like when you calibrate HD for superwhite (resolving up to 255) to resolve the highlights as per THX recommendations instead of calibrating in standard (resolving to 235, maybe 240 for a bit of headroom). When you do this in HD, you can show elusive highligths at the expense of peak brightness and on/off contrast at reference white. Something similar will happen in HDR. If you don't have a lot of brightness and on/off contrast in reserve, you will end up with a dimmer image in HDR/UHD compared to SDR/HD, so you'll wonder why your UHD bluray looks dimmer and less exciting than your standard bluray.

I could be completely wrong, but that's the way I see it for displays with a limited peak brightness like most consumer front projectors. Once we can get 5000 lumens from laser, this will completely change as long as we can keep a decent native contrast, but until then, I wouldn't expect miracles if your screen is significantly over 100" with nominal gain. I just can't see how it can happen.

Last edited by Manni01; 09-10-2015 at 05:00 PM.
Manni01 is offline  
post #44 of 80 Old 09-10-2015, 04:22 PM
AVS Forum Special Member
 
Ron Jones's Avatar
 
Join Date: Jul 2000
Location: SW Florida
Posts: 6,982
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 970 Post(s)
Liked: 993
Quote:
Originally Posted by Manni01 View Post
......., I wouldn't expect miracles if your screen is significantly over 100" with nominal gain. I just can't see how it can happen.

With a gain 1.0 screen of 130 inch diagonal (16 x 9) you only need 800 lumens to get the recommended 16 ftL. Thus the new JVC could produce highlights with about the twice as bright as reference white with this setup. Of course having 3000 lumens available for the highlights would be even better for HDR.

Ron Jones
Blog + Reviews + Articles: projectorreviews.com

Last edited by Ron Jones; 09-10-2015 at 05:05 PM.
Ron Jones is offline  
post #45 of 80 Old 09-10-2015, 04:51 PM
AVS Forum Special Member
 
Manni01's Avatar
 
Join Date: Sep 2008
Posts: 8,990
Mentioned: 307 Post(s)
Tagged: 0 Thread(s)
Quoted: 5345 Post(s)
Liked: 5383
Quote:
Originally Posted by Ron Jones View Post
With a gain 1.0 screen of 130 inch diagonal (16 x 9) you only need 800 lumens to get the recommended 16 ftL. Thus the new JVC could produce highlight with about the twice as bright as reference white with the setup. Of course have 3000 lumens available for the highlights would be even better for HDR.
Hi Ron.

Did you take into account D65 calibration as well as 25% additional brightness loss for the P3 filter, and are you thinking high lamp or low lamp?

The high lamp mode in the new models is apparently significantly noisier due to the more powerful bulb, while the low lamp mode should be about the same or a tad above (23db vs 22db, TBC).

So I was thinking low lamp with 100% of P3 and white to D65, but you're right that if we make compromises in PQ and/or SQ we can accommodate larger screens. For example the Sony 520ES which doesn't support P3 could of course light up a larger screen (they are noisier as well apparently at 26dB in low lamp).

Last edited by Manni01; 09-10-2015 at 04:56 PM.
Manni01 is offline  
post #46 of 80 Old 09-10-2015, 04:54 PM
 
RLBURNSIDE's Avatar
 
Join Date: Jan 2007
Posts: 3,901
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 2012 Post(s)
Liked: 1406
Quote:
Originally Posted by Mike Garrett View Post
Yes, HDR will have more range with a flat panel, but you are giving up too much size with most flat panels, to be able to rate the viewing experience as a whole, better on a flat panel.
I'd much rather so-so HDR on a projector than awesome HDR on a tiny (comparatively) screen
DavidHir and Mike Garrett like this.
RLBURNSIDE is offline  
post #47 of 80 Old 09-10-2015, 05:06 PM
AVS Forum Special Member
 
Manni01's Avatar
 
Join Date: Sep 2008
Posts: 8,990
Mentioned: 307 Post(s)
Tagged: 0 Thread(s)
Quoted: 5345 Post(s)
Liked: 5383
By the way, I stumbled on an interesting video summary about HDR from Joel/[email protected]:
Craig Peer likes this.
Manni01 is offline  
post #48 of 80 Old 09-10-2015, 05:38 PM
AVS Forum Addicted Member
 
mark haflich's Avatar
 
Join Date: Dec 2000
Location: Venice, Florida, USA
Posts: 21,464
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 1418 Post(s)
Liked: 1014
Hi Guys. Tough to get into this right now due to the passing of our friend, Cliffy.


Just a few comments about HDR. There really is no agreed standard. I think any manufacture which can get some peak white level above reference white will claim that its projector will do HDR. And many here will accept those claims. ergo, the manufacturer said its projector will do HDR and I don't care what you guys say.


We must go back and think about what HDR is, basically its being capable of displaying a wider range of F stops than SDR. What's an F stop? Well its basically a doubling of the amount of light and the numbers are logs. For example F11 will pass double the light of F16. F8 will pass double the light F11. Obviously the lower the black ref value, the more doubling can take place until one reaches peak white. But here is the kicker. Suppose you have a white ref of whatever when the projector is putting say 600 lumens. To double the light out you now need 1600 lumens and to double it from there you need 3200 lumens. Not that we can get anything like 2F stops above ref. And it takes 2 f stops to double the perceived brightness to your eyes.


Lets look at the max HDR being proposed. The Dolby standard which is also evolving based on practicality. A ref of say 100 and a peak of 1000 (whatever the not picking unit).Or is it 1000 and a peak of 10000? The point is 1oo doubled is 200, 200 doubled is 400, 400 doubled is 800. That's 3F stops plus a fraction of an f stop. That's HDR. Not the one F stop we might get with our light canon projectors. thank JVC for the big increase in projectile size. Its all a joke about HDR and projectors at this point. Panels can do it a lot easier. Even an OLED which stars with a really low black ref, just above oleds off. Doubling add maybe a f stop or 2 at the lowest end and maybe an f stop at the top is white ref is set at 500 a dim picture but HDR might look pretty good. But buying into a new projector to pick up at most 1 F stop of peak white. Not me or do I have it wrong. This whole HDR thing for projectors is mainly a marketing gimmick at this point or do I have it wrong? Maybe its looks a little better, every F stop counts when adding DR. But it ain't HDR in any stretch of the imagination.
mark haflich is offline  
post #49 of 80 Old 09-10-2015, 05:57 PM
AVS Forum Special Member
 
Ron Jones's Avatar
 
Join Date: Jul 2000
Location: SW Florida
Posts: 6,982
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 970 Post(s)
Liked: 993
Quote:
Originally Posted by Manni01 View Post
Hi Ron.

Did you take into account D65 calibration as well as 25% additional brightness loss for the P3 filter, and are you thinking high lamp or low lamp?

The high lamp mode in the new models is apparently significantly noisier due to the more powerful bulb, while the low lamp mode should be about the same or a tad above (23db vs 22db, TBC).

So I was thinking low lamp with 100% of P3 and white to D65, but you're right that if we make compromises in PQ and/or SQ we can accommodate larger screens. For example the Sony 520ES which doesn't support P3 could of course light up a larger screen (they are noisier as well apparently at 26dB in low lamp).

Ekki measured about 1600 lumens at near D65 for the X5000 and the X7000 and X9000 may be just a little higher. I didn't subtract the as yet unknown percent of lumens for when the P3 filter is used (only available on the X7000 and X9000). If you want to use HDR then I would certainly think you should be using high lamp mode, otherwise you are not really interested in getting what HDR can do for the bright highlights. Who knows, when in HDR mode the projector may force high lamp mode and also keep the iris fully open for scenes with bright highlights in order to produce the max. output for those highlights. Also to keep the brightness up for supporting HDR the projector should be mounted near the min. throw distance for the given screen size (i.e., max. zoom produces more lumens).
Manni01 likes this.

Ron Jones
Blog + Reviews + Articles: projectorreviews.com
Ron Jones is offline  
post #50 of 80 Old 09-10-2015, 06:09 PM
AVS Forum Special Member
 
Manni01's Avatar
 
Join Date: Sep 2008
Posts: 8,990
Mentioned: 307 Post(s)
Tagged: 0 Thread(s)
Quoted: 5345 Post(s)
Liked: 5383
Ekki did estimate the brightness loss associated with the P3 filter at 25% in his preview of the X5000, which is why I used this number. This was to be expected, and it's fairly good if confirmed as it's the same as the LS10000 and significantly better than the VW1x00ES which has a 40% drop.

For me, there is no HDR without P3 as I was comparing Bluray and UHD Bluray, so the X5000 is out.

Anyway, even in high lamp, your estimate is a bit optimistic, at least if we're talking about full UHD Bluray support (well bar native 4K as far as the JVCs are concerned).
Manni01 is offline  
post #51 of 80 Old 09-10-2015, 06:23 PM
AVS Forum Special Member
 
mo949's Avatar
 
Join Date: May 2012
Posts: 4,955
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 1193
Quote:
Originally Posted by stanger89 View Post

Going by the specs and the industry standards, if JVC (for example) can increase their brightness a bit, get it up to the 30fL of HDR in commercial cinemas, I think they've got a good story to sit on for supporting HDR..
I've not been getting a good feeling that they'll release the 30fl HDR graded content viewed at cinemas on UHD BLU. Instead I'm hearing it will be graded for 1000fl.

I'm not keen on watching content graded for 1,000FL+ on a 30FL setup.
mo949 is offline  
post #52 of 80 Old 09-10-2015, 06:53 PM
AVS Forum Addicted Member
 
stanger89's Avatar
 
Join Date: Nov 2002
Location: Marion, IA
Posts: 23,130
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 4156 Post(s)
Liked: 2384
Quote:
Originally Posted by mo949 View Post
I've not been getting a good feeling that they'll release the 30fl HDR graded content viewed at cinemas on UHD BLU. Instead I'm hearing it will be graded for 1000fl.

I'm not keen on watching content graded for 1,000FL+ on a 30FL setup.
It doesn't matter, read up some more on the HDR mastering process (eg the Dolby Vision white paper). With HDR white is not a fixed point like it is with Rec.709, it can be different things on different displays. Mastering monitors may go up to 2000 nits, but the EOTF supports up to 10,000 nits. The SMPTE 2084 metadata associated with the file describes the mastering monitor so that the end user display, be it a current HDR flat panel that can only do 1000 nits, a better one that can do 2000 nits, a projector that can do 100, will know how to appropriately display it. On a 100 nit display, you won't get highlights as bright as on a 1000 nit display, but the image shouldn't be "dimmer", average whites should be similar.

I would imagine that front projectors will bias things to be closer to a cinema output than a flat panel output, ie I'd guess they'll aim for "nominal" white to be in the 16fL (~50nits) range like we get today at home and in the cinema but, instead of the 30fL (100 nits)
.
stanger89 is offline  
post #53 of 80 Old 09-10-2015, 09:02 PM
AVS Forum Special Member
 
mo949's Avatar
 
Join Date: May 2012
Posts: 4,955
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 1193
This isn't about calibrating white point or the device using metadata to scale itselfdown. I'm talking the color grading the colorist dies for the cinema is at a different light output target than for home. Unless you are saying they won't regrade the content fir home consumption? Ie one color grading done for both.
mo949 is offline  
post #54 of 80 Old 09-10-2015, 11:43 PM
AVS Forum Addicted Member
 
mark haflich's Avatar
 
Join Date: Dec 2000
Location: Venice, Florida, USA
Posts: 21,464
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 1418 Post(s)
Liked: 1014
Quote:
Originally Posted by stanger89 View Post
It doesn't matter, read up some more on the HDR mastering process (eg the Dolby Vision white paper). With HDR white is not a fixed point like it is with Rec.709, it can be different things on different displays. Mastering monitors may go up to 2000 nits, but the EOTF supports up to 10,000 nits. The SMPTE 2084 metadata associated with the file describes the mastering monitor so that the end user display, be it a current HDR flat panel that can only do 1000 nits, a better one that can do 2000 nits, a projector that can do 100, will know how to appropriately display it. On a 100 nit display, you won't get highlights as bright as on a 1000 nit display, but the image shouldn't be "dimmer", average whites should be similar.

I would imagine that front projectors will bias things to be closer to a cinema output than a flat panel output, ie I'd guess they'll aim for "nominal" white to be in the 16fL (~50nits) range like we get today at home and in the cinema but, instead of the 30fL (100 nits)
.



On a 100 nit display, if the image isn't to be dimmer showing HDR, how will it be able to showing any HDR. The less the peak white capability, the white ref has to be lower to show even HDR diet. I get that source will take in the characteristics of the display and send it content to make it look best as someone chooses for us. Its not that it won't look OK on HDR light or diet HDR projectors. It will be better with HDR diet or light than non HDR. But it just won't be HDR.

Last edited by mark haflich; 09-11-2015 at 05:44 PM.
mark haflich is offline  
post #55 of 80 Old 09-11-2015, 04:46 AM
AVS Forum Addicted Member
 
stanger89's Avatar
 
Join Date: Nov 2002
Location: Marion, IA
Posts: 23,130
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 4156 Post(s)
Liked: 2384
Quote:
Originally Posted by mo949 View Post
This isn't about calibrating white point or the device using metadata to scale itselfdown. I'm talking the color grading the colorist dies for the cinema is at a different light output target than for home. Unless you are saying they won't regrade the content fir home consumption? Ie one color grading done for both.
We have the same issue today with Blu-ray. The Blu-ray master is made for TVs with two, to three times the brightness of projectors. I don't see anyone complaining about it today. The situation should be better for UHD BD, with HDR and SMPTE ST2086, what we see on projectors should be closer to what was seen on the mastering monitor than today where everything is just dimmer.
Manni01 likes this.
stanger89 is offline  
post #56 of 80 Old 09-11-2015, 09:29 AM
AVS Forum Special Member
 
mo949's Avatar
 
Join Date: May 2012
Posts: 4,955
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 1193
As to HDR requirements, its interesting that the minimum brightness requirements for flat panels is believed to be about 400 nits because the home HDR content will be graded with that minimum in mind. You may be ok with displaying that at 100 nits at home on a HDR compatible projector, but I would rather have the theatrical grade that's already graded for 100 nits. I've already been complaining about it myself I don't like the look of current bluray content stretched out to 180 nits like some people like to calibrate for.

But since it seems you now understand and aknowledge what I was pointing out, I'll leave it at that.

Last edited by mo949; 09-11-2015 at 09:33 AM.
mo949 is offline  
post #57 of 80 Old 09-11-2015, 03:51 PM
Senior Member
 
LumenChip's Avatar
 
Join Date: Mar 2015
Location: Canada
Posts: 366
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 222 Post(s)
Liked: 123
Quote:
Originally Posted by Manni01 View Post
By the way, I stumbled on an interesting video summary about HDR from Joel/[email protected]:
Some interesting discussion about HDR & UHD in general. The main take-away for me is the need for PQ remapping and variables introduced by the display and differing HDR standards. This means that depending on the implementation within the display the results can range from great to downright awful. I take it that the closer the displays brightness is to the HDR master's reference brightness, the better the odds that the display will have a good PQ remapping. Displays with a peak brightness that is well below the HDR reference brightness will likely have difficulty with the PQ remapping.
LumenChip is offline  
post #58 of 80 Old 09-14-2015, 01:40 PM
AVS Forum Special Member
 
mbw23air's Avatar
 
Join Date: Jul 2001
Location: KY
Posts: 3,063
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 205 Post(s)
Liked: 177
Sony just announced that it will be using Dolby Vision HDR on its upcoming UHD blurays. It will be interesting to see which HDR is preferred(better), regular HDR vs. Dolby Vision's HDR. It might really depend on how it is implemented by the person(s) doing the transfer and 1 method vs. the other might be the same.

http://www.blu-ray.com/news/?id=17574

Mike
DavidHir likes this.
mbw23air is offline  
post #59 of 80 Old 09-14-2015, 04:13 PM
AVS Forum Special Member
 
blazar's Avatar
 
Join Date: Oct 2004
Location: USA
Posts: 4,322
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1188 Post(s)
Liked: 876
Ive got a 160" 1.0 screen and I throw distance around 24 feet... I will likely be waiting forever for a 4k projector with adequate brightness AND a reasonable price range much less HDR.

I agree with earlier comments that "home" projectors with adequate brightness are unlikely to emerge anytime soon.

My wallet will have to continue to get fatter while I wait.

Blazar!
blazar is offline  
post #60 of 80 Old 09-14-2015, 04:30 PM
AVS Forum Addicted Member
 
DavidHir's Avatar
 
Join Date: Dec 2004
Posts: 14,251
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 2520 Post(s)
Liked: 2196
Quote:
Originally Posted by blazar View Post
Ive got a 160" 1.0 screen and I throw distance around 24 feet... I will likely be waiting forever for a 4k projector with adequate brightness AND a reasonable price range much less HDR.

I agree with earlier comments that "home" projectors with adequate brightness are unlikely to emerge anytime soon.

My wallet will have to continue to get fatter while I wait.
160" with 1.0 gain, wow. Black pit room? What kind of projector?
DavidHir is offline  
Sponsored Links
Advertisement
 
Reply Digital Hi-End Projectors - $3,000+ USD MSRP

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off