Presentation I gave last week to ICDM group at SID about CR with front projection - Page 3 - AVS Forum | Home Theater Discussions And Reviews
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post #61 of 194 Old 09-08-2016, 06:09 PM
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Originally Posted by Stereodude View Post
I'm quite certain Darin isn't making any leaps of faith. He knows his stuff.
Yes, Darin does know his stuff. But the example I posed suggests why the method may break down. And so, it is reasonable to doubt it as the best measure of contrast for low APL content. Look at the measured low APL contrast numbers for the X500 that stanger89 posted:
Quote:
Originally Posted by stanger89 View Post
Projectiondream does a really good job with their multi-APL contrast testing:
http://projectiondream.com/en/jvc-dl...iew-projector/
You will notice that the measured contrast correlates roughly to
(ANSI contrast)x(50%) / (%white_in_test_pattern).

from the projectiondream x500 review:

"ideal perfect room (at lens)" contrast measurements (no iris):
..........measured
condition contrast ANSI*(50%)/(%white)

On/Off.. 20132

....1%.. 10192 .13900 = 50/1*278
....2%... 7320 ..6950
= 50/2*278
....5%... 3098 ..2780 = 50/5*278
...10%... 1844 ..1390 = 50/10*278

...20%.... 938 ...695 = 50/20*278
..ANSI.... 278


So to me, it seems like (for the JVCs) the real contrast level is directly related to the ANSI contrast. That is, until it gets limited by the on/off contrast.
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post #62 of 194 Old 09-08-2016, 06:21 PM - Thread Starter
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So to me, it seems like (for the JVCs) the real contrast level is directly related to the ANSI contrast. That is, until it gets limited by the on/off contrast.
The "real contrast" level is related to ANSI CR specifically for the reasons I gave about having two factors. One is the black floor and one is the washout effect. The reason you see it track like ANSI CR to a certain degree is specifically because the sequential CR is high. That is, the black floor is low, so the washout effect is what matters.

If sequential CR was low then it would come into play in much brighter images than it does. The whole point here is that JVC has largely made the sequential CR high enough that it doesn't create problems until the images are very dark.

There used to be a site where you could plug in different numbers for ANSI CR and sequential CR and see how it was likely to affect images in between.

For a case like DLPs can have with high ANSI CR and lower on/off CR you can look at some example numbers I provided in an article about 10 years ago here (under Future Improvements):

http://hometheaterhifi.com/volume_13...06-part-5.html

You are welcome to try your equations with something like 2k:1 sequential CR and 500:1 ANSI CR and then see if the intra-image CRs really track ANSI CR, especially in the images where CR is weak (since those are where it matters most).

There are good reasons that we would have been much better off if DLPs had advanced their sequential CRs since I requested that, where advancing their ANSI CRs from where they were 10 years ago wouldn't have made much difference.

With just about anything here the most important factor to fix is the one that is the weakest with a particular model. That could be color accuracy, resolution, ANSI CR, on/off CR, motion, etc. A display being great at one of those doesn't mean that factor doesn't matter. Just that they've made that area good so it doesn't get in the way of quality video.

--Darin
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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."

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post #63 of 194 Old 09-08-2016, 07:07 PM
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Originally Posted by darinp2 View Post
Excuse me. What are you asking? Are you asking whether it is okay to use different numbers than I did, or are you seriously asking what would be wrong with images from movies if the white level was 500 cd/m2 and the black floor was 1 cd/m2. 500:1 is like those horrible Sony LCD BVM monitors they tried to foust on mastering houses years ago. Much better ANSI CR than the CRT BVM monitors, but horrible grey blacks with movies overall. That is what 500:1 does to movies. Pitiful and anybody who loves movies and is happy with 500:1 sequential CR must not care about image quality very much.
No, DCI already includes sequential CR and not sure what you are claiming about SMPTE since many of their experts already understand that sequential CR matters. The DCI group knows that commercial theaters bright special challenges, but they do not dismiss sequential CR like you clim. Minimum off the screen sequential CR is specified, but not maximum.
Intra-frame Contrast for real images is affected by both the floor from Sequentual CR and the washout largely from ANSI CR. Did you not understand my presentation?

--Darin
DCI plainly states,

Digital Cinema System Specification
Compliance Test Plan
Version 1.2
October 10, 2012


7.5.7. Sequential Contrast
Objective
Measure the sequential contrast ratio of the Projector.
Procedures
Note: Prior to taking measurements, ensure that the projector setup and test environment requirements detailed in
Section 7.1 have been performed.
1. Measure the luminance at the center of the screen for the "full black" test pattern contained in the DCP Sequential
Contrast and Uniformity Sequence.
2. Measure the luminance at the center of the screen for the "full white" test pattern contained in the DCP Sequential
Contrast and Uniformity Sequence.
3. Compute the sequential contrast ratio by dividing the white luminance value by the black luminance value.
4. Record the calculated value.
Supporting Materials
Reference Document ID Reference Document Section(s)
[DCI-DCSS-1-2] 8.3.4.7
Test Equipment
Photometer
Test Material
Sequential Contrast and Uniformity Sequence

7.5.8. Intra-frame Contrast
Objective
Measure the intra-frame contrast ratio of the Projector.
Procedures
Note: Prior to taking measurements, ensure that the projector setup and test environment requirements detailed in
Section 7.1 have been performed.
1. Display the checkerboard test pattern Intra-Frame Contrast Sequence.
2. Measure the luminance level at each of the patches in the checkerboard test pattern.
3. Calculate the average value of the luminance of the white patches and divide by the average value of the luminance
of the black patches.
4. Record the calculated value.
Supporting Materials
Reference Document ID Reference Document Section(s)
[DCI-DCSS-1-2] 8.3.4.8
[SMPTE-431-2]
Test Equipment
Photometer
Test Material
Intra-Frame Contrast Sequence

Sorry, I can't provide the reference docs in an open forum, they get mad, and it is an Encrypted MXF file.

Actually, SMPTE is revisiting all of this next year.

And the payoff is never certain: Some observers contend that a generation has already been trained to be content with the small screen.

Some servers can do non-encrypted playback to an A/V projector, but it's just a ridiculously expensive media player if you don't have a cinema projector.
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post #64 of 194 Old 09-08-2016, 07:16 PM
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Quote:
Originally Posted by darinp2 View Post
...Either the black floor can be a problem or that washout from bright parts of the image to darker.
Agreed.

Quote:
Originally Posted by darinp2 View Post
With bad enough ANSI CR it can of course be the determining factor, but with 100:1 system ANSI CR or high the sequential CR can be a much bigger factor for how black the blacks are in those dark images.
Agreed, but a 100:1 ANSI implies one might be at only 5K:1 for a 1% contrast pattern, even with on/off at 100k:1.


Quote:
Originally Posted by darinp2 View Post
While tests like that are good, if I can only have 2 specs I want extremes that allow me to calculate values in between pretty well. With the black floor and the washout effect I can estimate many of the images you want to know about, but if you only give me images in between the extremes then it is hard to determine the extremes.
I must have missed that you want both ANSI and on/off. (I have seen many posts that argue for on/off as the most important). So my bad. But I don't think it was made very clear in the Z1 thread that the on/off is just a tool to help predict what contrast you will get at low APL scenes.

I agree these 2 measures are better than just ANSI or just on/off. But I would still rather see a contrast measured at a large range of APLs (which includes on/off all the way to 50%).


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Originally Posted by darinp2 View Post
... with pieces of information we can make valid conclusions about some things. People seem to get hooked on things like on/off CR not telling you exactly how a dark mixed scene will do. Of course it doesn't. It provides one piece of that puzzle and combined with other pieces provides a lot of information.
Agree.
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post #65 of 194 Old 09-08-2016, 07:45 PM
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Originally Posted by darinp2 View Post
The "real contrast" level is related to ANSI CR specifically for the reasons I gave about having two factors. One is the black floor and one is the washout effect. The reason you see it track like ANSI CR to a certain degree is specifically because the sequential CR is high. That is, the black floor is low, so the washout effect is what matters.

If sequential CR was low then it would come into play in much brighter images than it does. The whole point here is that JVC has largely made the sequential CR high enough that it doesn't create problems until the images are very dark.

There used to be a site where you could plug in different numbers for ANSI CR and sequential CR and see how it was likely to affect images in between.

For a case like DLPs can have with high ANSI CR and lower on/off CR you can look at some example numbers I provided in an article about 10 years ago here (under Future Improvements):

http://hometheaterhifi.com/volume_13...06-part-5.html

You are welcome to try your equations with something like 2k:1 sequential CR and 500:1 ANSI CR and then see if the intra-image CRs really track ANSI CR, especially in the images where CR is weak (since those are where it matters most).

There are good reasons that we would have been much better off if DLPs had advanced their sequential CRs since I requested that, where advancing their ANSI CRs from where they were 10 years ago wouldn't have made much difference.

With just about anything here the most important factor to fix is the one that is the weakest with a particular model. That could be color accuracy, resolution, ANSI CR, on/off CR, motion, etc. A display being great at one of those doesn't mean that factor doesn't matter. Just that they've made that area good so it doesn't get in the way of quality video.

--Darin
You talk like one of the Sony guys, everything is TI's fault. Look if LCOS, or for that matter, D-ILA was any good at the commercial cinema, they would be offered. No theater owner in North America wants's anything without a Texas Instruments m25 DLP Cinema light engine because of it's performance, reliability, and parts availability.

And the payoff is never certain: Some observers contend that a generation has already been trained to be content with the small screen.

Some servers can do non-encrypted playback to an A/V projector, but it's just a ridiculously expensive media player if you don't have a cinema projector.
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Look if LCOS, or for that matter, D-ILA was any good at the commercial cinema, they would be offered. No theater owner in North America wants's anything without a Texas Instruments m25 DLP Cinema light engine because of it's performance, reliability, and parts availability.
And none of that means DLP is a better solution at home. So, what's your point?
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post #67 of 194 Old 09-08-2016, 09:53 PM - Thread Starter
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DCI plainly states ...
The rest supports what I already told you, so why did you even make this post? Did you mean to finally admit that what I told you is true? Or was it an accident that you supported what I said?

DCI includes sequential CR while you disparage it (based on your own ignorance).

I know the moderators have a tough job, but is there any point that somebody like CinemaAndy will get suspended or banned for intellectual dishonesty and trying to deceive readers on AVS? He already largely ruined another thread and then all of the posts that showed his dishonesty went away along with all of the responses showing what he was doing. So, he gets to largely start over trying to deceive without people seeing the history.

There is no way it is an accident that he continues to claim he is right despite the evidence.

If it were my forum I would ban people for purposeful deception like that from CinemaAndy, or at minimum a 2 week suspension.

People coming to AVScience shouldn't have to put up with deceptions like those from CinemaAndy. It is hard enough for many to grasp all the technical issues without the immoral types who want to deceive readers being allowed to take advantage of this place.

--Darin

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Originally Posted by darinp2 View Post
The rest supports what I already told you, so why did you even make this post? Did you mean to finally admit that what I told you is true? Or was it an accident that you supported what I said?

DCI includes sequential CR while you disparage it (based on your own ignorance).

I know the moderators have a tough job, but is there any point that somebody like CinemaAndy will get suspended or banned for intellectual dishonesty and trying to deceive readers on AVS? He already largely ruined another thread and then all of the posts that showed his dishonesty went away along with all of the responses showing what he was doing. So, he gets to largely start over trying to deceive without people seeing the history.

There is no way it is an accident that he continues to claim he is right despite the evidence.

If it were my forum I would ban people for purposeful deception like that from CinemaAndy, or at minimum a 2 week suspension.

People coming to AVScience shouldn't have to put up with deceptions like those from CinemaAndy. It is hard enough for many to grasp all the technical issues without the immoral types who want to deceive readers being allowed to take advantage of this place.

--Darin
It is how the contrast measurements are read, and how that information is represented, that is my problem with it, over half the so called experts on here use the wrong instrument, wrong screen calibration, wrong math and a bunch of other wrongs to get to some highly unrealistic contrast number, then put that number up for all to believe. That has been my point all along. Take it or leave it.

And the payoff is never certain: Some observers contend that a generation has already been trained to be content with the small screen.

Some servers can do non-encrypted playback to an A/V projector, but it's just a ridiculously expensive media player if you don't have a cinema projector.
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over half the so called experts on here use the wrong instrument, wrong screen calibration, wrong math and a bunch of other wrongs to get to some highly unrealistic contrast number,
You are too clueless to know who is doing it right, what realistic numbers are, what they mean, what they don't mean, or to even answer a simple math question I ask you, despite people trying to help you shed that ignorance you have clearly held onto for years. You might as well tell us that your point is that the earth is flat. You would be about as right as you've been here.

My guess is that next year you'll be just as ignorant as you've been the last decade. Some people don't have enough intellectual integrity to ever learn anything.

--Darin
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BTW: People may notice that CinemaAndy ignores Dolby Cinema in the commercial theater area, where they can do over 120k:1 if the room lights can be low enough (it is possible that some jurisdiction don't allow the room to be that dim). The Dolby Cinema CRs are real and do matter despite ignorant claims from people like CinemaAndy.

When I talked to the company that Dolby ended up buying over a decade ago we marveled at how ignorant many people in the industry are, with CinemaAndy fitting that bill perfectly even though we didn't know him. That company asked me if I wanted to work on one of their projects since they knew I understood CR.

There were also multiple Dolby people at the presentation I made and they gave me very positive feedback for helping correct some of the misinformation in the industry about CR.

CinemaAndy wouldn't be able to keep up with the Dolby guys on this subject matter.

--Darin
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The "real contrast" level is related to ANSI CR specifically for the reasons I gave about having two factors. ...
Off topic, but have you seen any measurements of ANSI contrast for the RS500/RS600 projectors?
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Originally Posted by darinp2 View Post
I know the moderators have a tough job, but is there any point that somebody like CinemaAndy will get suspended or banned for intellectual dishonesty and trying to deceive readers on AVS? He already largely ruined another thread and then all of the posts that showed his dishonesty went away along with all of the responses showing what he was doing. So, he gets to largely start over trying to deceive without people seeing the history.

There is no way it is an accident that he continues to claim he is right despite the evidence.

If it were my forum I would ban people for purposeful deception like that from CinemaAndy, or at minimum a 2 week suspension.

People coming to AVScience shouldn't have to put up with deceptions like those from CinemaAndy. It is hard enough for many to grasp all the technical issues without the immoral types who want to deceive readers being allowed to take advantage of this place.

--Darin
Doubtful, you'll probably get infractions for the last few posts while he escapes any sort of punishment and laughs at the chaos he's causing.
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post #73 of 194 Old 09-09-2016, 12:17 PM
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Originally Posted by darinp2 View Post
BTW: People may notice that CinemaAndy ignores Dolby Cinema in the commercial theater area, where they can do over 120k:1 if the room lights can be low enough (it is possible that some jurisdiction don't allow the room to be that dim). The Dolby Cinema CRs are real and do matter despite ignorant claims from people like CinemaAndy.

When I talked to the company that Dolby ended up buying over a decade ago we marveled at how ignorant many people in the industry are, with CinemaAndy fitting that bill perfectly even though we didn't know him. That company asked me if I wanted to work on one of their projects since they knew I understood CR.

There were also multiple Dolby people at the presentation I made and they gave me very positive feedback for helping correct some of the misinformation in the industry about CR.

CinemaAndy wouldn't be able to keep up with the Dolby guys on this subject matter.

--Darin
Darin, now your adding words I did not say. I have had a great working relationship with Dolby for decades, likewise with Christie Digital. The work that both Dolby, Texas Instruments, Harkness screens and Christie did in achieving the Dolby Cinema houses around the world was a combination of many things and many people working long hours. Many standards were made, and rewritten and rewritten again during the process. Both Dolby and Christie knew that without improving on screen clarity in the image, it would be for nothing. I dropped by more than once while they were setting up the old Vine theater on Hollywood and Vine in LA to persuade executives and chain owners to buy in, and it worked.

You can't replicate a Dolby cinema anywhere else. Every part of it is copyrighted. You can't buy or lease the equipment. Sure you can get 6P projectors from Christie, but not the model a Dolby Cinema uses, likewise for the Dolby CP850 is a licensed and leased product, the seating, the lighting, the design is all copyrighted.

I have seen 1,000,000:1 Full on/off and 150,000:1 ANSI on a Dolby screen playing a test image. I have yet to see those numbers with content playing. That still does not detract from the Dolby Cinema experience of HDR.

I don't do Dolby Cinema constructions, they have their own people. I was offered the job, however, I have no plans to give up my independence. The cinema industry is tricky even in good times. I work with many different product companies and many different theater owners from a one screen theater to 30 screens, the hardest sell is always convincing the theater owner that upgrades equal profits, despite holding out my hand for hundreds of thousands or millions of dollars for the work. Everything but easy, each owner has the right to present the movies how they want.

My dad spent most of his entire working life in the sound department at Disney studios, except for a few years in the late 70's he has lured away, to work at Dolby Labs by Ray Dolby. I don't have to keep up with the Dolby guys, I know them.

I also know plenty of people like you. Always saying what is wrong in the industry, and we always twiddle our thumbs, because we know, we have been there, we have already had the discussion and are not amused to be having it again.

And the payoff is never certain: Some observers contend that a generation has already been trained to be content with the small screen.

Some servers can do non-encrypted playback to an A/V projector, but it's just a ridiculously expensive media player if you don't have a cinema projector.
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Off topic, but have you seen any measurements of ANSI contrast for the RS500/RS600 projectors?
http://pro.jvc.com/pro/pr/2015/releases/jvc_cedia.html

Native contrast ratio of 150,000:1

Dynamic contrast to 1,500,000:1

265W high-power lamp

I would hate to see what they called a low powered lamp.

DLA-X950R/RS600 1,900lm

DLA-X750R/RS500 1,800lm

As a guess, I would put the ANSI around 6,000:1 based on the Native and Dynamic, and a more realistic on screen 900 lumens. The one spec that bugs me is the 4K 60p 4:4:4 it was my understanding the current HDCP2.2 didn't have the bandwidth to support 4:4:4 or maybe they are supplementing it for RGB color space, lots of that going on.

And the payoff is never certain: Some observers contend that a generation has already been trained to be content with the small screen.

Some servers can do non-encrypted playback to an A/V projector, but it's just a ridiculously expensive media player if you don't have a cinema projector.
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Off topic, but have you seen any measurements of ANSI contrast for the RS500/RS600 projectors?
i don't recall seeing specific numbers, but based on other JVCs I'm thinking somewhere around 300:1 before the room diminishes it further.

The highest I've measured with any projector was about 1000:1 with a single chip Marantz DLP with a long throw lens. It still had relatively poor looking blacks for dark scenes though because the on/off CR wasn't that high and was the limiting factor in most of those scenes.

--Darin
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CinemaAndy,

You say you've seen 1,000,000:1 full on/off CR with the Dolby Cinema unit with test images. Given that this is a sequential CR it doesn't really need to have that much CR within a single image to be relevant. That on/off CR defines the black floor once you know the white level. For example, if the white level is 100 nits then that on/off CR means that the absolute black floor is 0.0001 nits. The could be being conservative and it is actually lower.

That low black floor is relevant to dark images in real content. With the same white level only 2000:1 on/off CR would mean a black floor of 0.05 nits.

Have you been able to see any advantage from the low black floor with the Dolby Cinema units, or do they look the same to you in dark scenes as DLP projectors with much lower on/off CR?

Many of us can reduce the lighting in our theater rooms to take advantage of high on/off CR in dark scenes.

--Darin
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Originally Posted by CinemaAndy View Post
http://pro.jvc.com/pro/pr/2015/releases/jvc_cedia.html

Native contrast ratio of 150,000:1

Dynamic contrast to 1,500,000:1

265W high-power lamp

I would hate to see what they called a low powered lamp.

DLA-X950R/RS600 1,900lm

DLA-X750R/RS500 1,800lm

As a guess, I would put the ANSI around 6,000:1 based on the Native and Dynamic, and a more realistic on screen 900 lumens. The one spec that bugs me is the 4K 60p 4:4:4 it was my understanding the current HDCP2.2 didn't have the bandwidth to support 4:4:4 or maybe they are supplementing it for RGB color space, lots of that going on.
Here you just show off your ignorance.

In most HT´s 1900 lumens on a calibrated RS600 is more than enough (calibrated to D65 the RS600 has around 1800 lumens with a new lamp), and in high mode on a 1.0 gain screen with a normal size it can do about 3 times brighter than the THX standard. Do you know the standard? Most RS600 owners have to turn the manual iris down to adjust the brightness down to a non eye fatiguing brightness. In my HT in 2.35:1 mode and almost 11 feet wide (quite big in a normal HT with 6 seats) 1.0 gain screen I turn the iris down 8 steps of 15 to get around 18fl (I like it bright) and this gives me a native on/off around 75000:1 (can you tell me the blacklevel in fl?) in 16x9 mode I turn it down to 12 (still 18fl) and get around 100000:1 (the blacklevel is easy to figure out with this number) on/off. The dynamic contrast of a RS600 is around 7-800000:1 if you leave the manual iris at 0 and the DI on, so yes the 1500000:1dynamic is not a realistic number, but the native is as I and several others (including Cine4home) have measured several RS600 to around 150000:1 with the manual iris set to 15 and the DI off. And I use the right equipment and I know how to use it, but I have a big doubt you do.

6000:1 ANSI on a projector?? LOL! Do you actually know how to measure ANSI contrast??

Last edited by Andreas21; 09-09-2016 at 02:57 PM.
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post #78 of 194 Old 09-09-2016, 03:14 PM
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...The one spec that bugs me is the 4K 60p 4:4:4 it was my understanding the current HDCP2.2 didn't have the bandwidth to support 4:4:4.
Did you mean HDMI 2.0? HDCP2.2 is a copy protection spec. HDMI 2.0 allows 600M/s pixel rate (@30 bits/pixel, 24 of which are data). (~1.2) x3840x2160x60fps = 597M pixels/sec. So it can do 4k60p 4:4:4 for 8 bit. But that is at the limit, and only with the best of cables.
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Originally Posted by darinp2 View Post
i don't recall seeing specific numbers, but based on other JVCs I'm thinking somewhere around 300:1 before the room diminishes it further.

The highest I've measured with any projector was about 1000:1 with a single chip Marantz DLP with a long throw lens. It still had relatively poor looking blacks for dark scenes though because the on/off CR wasn't that high and was the limiting factor in most of those scenes.

--Darin
Thanks, I did find it https://translate.google.com/transla...-text=&act=url
and you were remarkably close.

"c) The ANSI (checkerboard) contrast has not changed in the new generation, it is in the series average at 320: 1 (all models). Here is recorded an increase over the previous generation, helps the bright picture scenes to more plasticity."
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Did you mean HDMI 2.0? HDCP2.2 is a copy protection spec. HDMI 2.0 allows 600M/s pixel rate (@30 bits/pixel, 24 of which are data). (~1.2) x3840x2160x60fps = 597M pixels/sec. So it can do 4k60p 4:4:4 for 8 bit. But that is at the limit, and only with the best of cables.
I know HDCP2.2 is copy protection, a lot of people were saying it was mucking up the UHD process by limiting the bandwidth in the HDMI cable. Guess they got it straightened out.

And the payoff is never certain: Some observers contend that a generation has already been trained to be content with the small screen.

Some servers can do non-encrypted playback to an A/V projector, but it's just a ridiculously expensive media player if you don't have a cinema projector.
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Originally Posted by Andreas21 View Post
Here you just show off your ignorance.

In most HT´s 1900 lumens on a calibrated RS600 is more than enough (calibrated to D65 the RS600 has around 1800 lumens with a new lamp), and in high mode on a 1.0 gain screen with a normal size it can do about 3 times brighter than the THX standard. Do you know the standard? Most RS600 owners have to turn the manual iris down to adjust the brightness down to a non eye fatiguing brightness. In my HT in 2.35:1 mode and almost 11 feet wide (quite big in a normal HT with 6 seats) 1.0 gain screen I turn the iris down 8 steps of 15 to get around 18fl (I like it bright) and this gives me a native on/off around 75000:1 (can you tell me the blacklevel in fl?) in 16x9 mode I turn it down to 12 (still 18fl) and get around 100000:1 (the blacklevel is easy to figure out with this number) on/off. The dynamic contrast of a RS600 is around 7-800000:1 if you leave the manual iris at 0 and the DI on, so yes the 1500000:1dynamic is not a realistic number, but the native is as I and several others (including Cine4home) have measured several RS600 to around 150000:1 with the manual iris set to 15 and the DI off. And I use the right equipment and I know how to use it, but I have a big doubt you do.

6000:1 ANSI on a projector?? LOL! Do you actually know how to measure ANSI contrast??
THX is a reference, not a standard.

And the payoff is never certain: Some observers contend that a generation has already been trained to be content with the small screen.

Some servers can do non-encrypted playback to an A/V projector, but it's just a ridiculously expensive media player if you don't have a cinema projector.
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Andy,
Are you attending Cedia next week?

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post #83 of 194 Old 09-09-2016, 08:25 PM
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Originally Posted by darinp2 View Post
CinemaAndy,

You say you've seen 1,000,000:1 full on/off CR with the Dolby Cinema unit with test images. Given that this is a sequential CR it doesn't really need to have that much CR within a single image to be relevant. That on/off CR defines the black floor once you know the white level. For example, if the white level is 100 nits then that on/off CR means that the absolute black floor is 0.0001 nits. The could be being conservative and it is actually lower.

That low black floor is relevant to dark images in real content. With the same white level only 2000:1 on/off CR would mean a black floor of 0.05 nits.

Have you been able to see any advantage from the low black floor with the Dolby Cinema units, or do they look the same to you in dark scenes as DLP projectors with much lower on/off CR?

Many of us can reduce the lighting in our theater rooms to take advantage of high on/off CR in dark scenes.

--Darin
Dolby's Vine theater is lighted in blue, like the Eindhoven, JT Eindhoven, however, AMC and Dolby went with red. Dolby actually got an exemption for the LA fire department to light the exit signs blue, as well as the walkway lights. However the Vine is only a 70 seat semi-private theater, and they can and regularly do turn all the lights off. AMC does not have that luxury as fire codes vary from state to state and they had to stick with red exit signs. But a lot of testing showed that red lights, used on many ships' bridges and airplane cockpits, was the least distractive and easiest to manage. The AMC Dolby does lower the lights 10% further than the norm.

Dolby is not alone, there is plenty of competition in the "luxury" theater market. IMAX has chosen Barco's 6P 4K rigs, and like Dolby Cinema are using twin projectors, there is also countless large screen formats, AVX, D-CInema, etc.

When Christie and Barco premiered there 6P laser projectors here in Galveston at Moody Gardens in 2012 we were all impressed, even Peter was impressed, with the 3D. The one thing I noticed right away, was that you could see the micro perf's in the semi-perf Harkness screen, that distracted for the viewing experience, even on a 60 x 80-foot screen but you could not argue with the image quality being projected, some of the brightest and highest contrast ever projected. Don Kempf, president and founder of D3D Cinema, said Christie was working with Harkness on the perf issue and Harkness rolled out a high gain woven screen just for Dolby Theatres and most others are using Harkness Clarus XC 170 screen.

No, the black levels of the Dolby Cinema are much crisper than even the normal DLP 6P projectors. So much so a few films had to be re-graded for objects hidden in the dark, to stay there until the camera panned closer, Jurrasic World is one such film.

Stuart Bowling at Dolby is who you want to talk with about Dolby Cinema. But, don't expect him to spill the beans on their HDR Cinema and don't bother asking about HT usage.

And the payoff is never certain: Some observers contend that a generation has already been trained to be content with the small screen.

Some servers can do non-encrypted playback to an A/V projector, but it's just a ridiculously expensive media player if you don't have a cinema projector.
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Originally Posted by Ericglo View Post
Andy,
Are you attending Cedia next week?
Yeah for one day. Don't know what day yet, depends on how things are going my project in Austin. I want to see Barco's residential booth and a few others.

And the payoff is never certain: Some observers contend that a generation has already been trained to be content with the small screen.

Some servers can do non-encrypted playback to an A/V projector, but it's just a ridiculously expensive media player if you don't have a cinema projector.
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Originally Posted by CinemaAndy View Post
No, the black levels of the Dolby Cinema are much crisper than even the normal DLP 6P projectors. So much so a few films had to be re-graded for objects hidden in the dark, to stay there until the camera panned closer, Jurrasic World is one such film.
Do you dispute that the main reason for what you describe there is due to the high sequential CR the Dolby system is able to achieve?

The low black floor is defined by the white level and the sequential CR.

--Darin
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Originally Posted by CinemaAndy View Post
Yeah for one day. Don't know what day yet, depends on how things are going my project in Austin. I want to see Barco's residential booth and a few others.
Darin, I and a lot of others will be there all three days. It might be easier to hash this out in person.

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post #87 of 194 Old 09-09-2016, 10:24 PM
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THX is a reference, not a standard.
THX is a standard. That was the whole point of THX: to bring movie theaters up to a certain level of performance, THX developed STANDARDS for theaters to meet in order to be THX certified. (The fact that it would be voluntary for a theater to conform to THX standards doesn't mean they aren't "standards.")

You completely ignored everything Andreas21 wrote that demonstrated how out to lunch you were in your understanding of the JVC projector brightness and home application, and instead reply with a red herring comment.

And...6,000:1 ANSI ? That was your guess?

You keep portraying yourself as experienced, yet virtually everyone here would know that 6,000:1 ANSI
is an insane number for current consumer projectors (remember that's ANSI contrast, NOT sequential on/off - you seem to mix up the two). JVC has been stuck at around 300:1 ANSI for many years and most people here know that. Other consumer projector technologies aren't that much higher. Anyone technically familiar with home theater projectors would know 6000:1 ANSI is a complete pipe dream. Don't you think that someone bashing certain home theater projectors, lecturing us on their technical demerits, should have the intellectual integrity to first know what the hell he is talking about, rather than make out-to-lunch statements about brightness and ANSI contrast to an audience who knows better?

BTW ANSI isn't the whole story as to the type of simultaneous contrast you will see on screen. As you can see from Darin's demonstrations, depending on the type of shot (e.g. low APL scenes, or dark scenes with high contrast bright elements), you will often benefit greatly from high native on/off contrast, like the JVCs offer, which will produce a higher contrast simultaneous image than the ANSI measurements would lead you to believe, and a higher contrast image than some projectors measuring higher in ANSI contrast.

People here are giving you actual real world experience with these projectors, and giving you the actual measurements that show you are wrong over and over.

Seriously, what do you have against ever admitting you are wrong, acknowledging the possible value of anything anyone else contributes, and actually learning something new?

(And, btw, if anything I've written above is incorrect, I would happily welcome correction from someone informed...unlike someone else we know in this thread)
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post #88 of 194 Old 09-09-2016, 11:20 PM
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Originally Posted by darinp2 View Post
Do you dispute that the main reason for what you describe there is due to the high sequential CR the Dolby system is able to achieve?

The low black floor is defined by the white level and the sequential CR.

--Darin
No, there is no main reason really, there is a lot of factors. Like screen brightness. Dolby, TI, and Christie are really guarding the HDR light engine, there even doing the lamp changes along with remote monitoring of performance. Not just that, everything related to it, the media server, software, you name it.

One of the DCP 4K test films, had a cup of black coffee, in a white cup, black table cloth, white table and checkerboard white/black walls, ceiling, and floor. A man wearing a black shirt and white pants, black shoes walk in and took a seat at the table in a black chair, a woman walks in wearing a white blouse and a black skirt with white shoes and sits in the other white chair. The camera pans around the room, Slowly zooming out, then slowly zooming in and you never loose the image, it was beyond OLED quality on a 60-foot screen, the image brightened and darkened as the camera panned by a window, again the image quality was superb, then the guy picks up a white straw and as he his about to stir the coffee, you can see his reflection in it. There is probably not even a hand full of projectors that could do something like that and get it right. Talking about it does not do it justice. That is something you simply have to see.

The limiting factor with Dolby Cinema right now is a lack of content. A lot of the studios like it, they just will not commit to the extra money for 6 or 8K recording that HDR requires. 7 movies so far this year in native 4K. DCI, after two and a half years of enthusiastic debate, decided they wouldn’t need to make that call and would let the producers decide and let the market decide. That is that as they say.

And the payoff is never certain: Some observers contend that a generation has already been trained to be content with the small screen.

Some servers can do non-encrypted playback to an A/V projector, but it's just a ridiculously expensive media player if you don't have a cinema projector.
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post #89 of 194 Old 09-09-2016, 11:41 PM
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Originally Posted by R Harkness View Post
THX is a standard. That was the whole point of THX: to bring movie theaters up to a certain level of performance, THX developed STANDARDS for theaters to meet in order to be THX certified. (The fact that it would be voluntary for a theater to conform to THX standards doesn't mean they aren't "standards.")

You completely ignored everything Andreas21 wrote that demonstrated how out to lunch you were in your understanding of the JVC projector brightness and home application, and instead reply with a red herring comment.

And...6,000:1 ANSI ? That was your guess?

You keep portraying yourself as experienced, yet virtually everyone here would know that 6,000:1 ANSI
is an insane number for current consumer projectors (remember that's ANSI contrast, NOT sequential on/off - you seem to mix up the two). JVC has been stuck at around 300:1 ANSI for many years and most people here know that. Other consumer projector technologies aren't that much higher. Anyone technically familiar with home theater projectors would know 6000:1 ANSI is a complete pipe dream. Don't you think that someone bashing certain home theater projectors, lecturing us on their technical demerits, should have the intellectual integrity to first know what the hell he is talking about, rather than make out-to-lunch statements about brightness and ANSI contrast to an audience who knows better?

BTW ANSI isn't the whole story as to the type of simultaneous contrast you will see on screen. As you can see from Darin's demonstrations, depending on the type of shot (e.g. low APL scenes, or dark scenes with high contrast bright elements), you will often benefit greatly from high native on/off contrast, like the JVCs offer, which will produce a higher contrast simultaneous image than the ANSI measurements would lead you to believe, and a higher contrast image than some projectors measuring higher in ANSI contrast.

People here are giving you actual real world experience with these projectors, and giving you the actual measurements that show you are wrong over and over.

Seriously, what do you have against ever admitting you are wrong, acknowledging the possible value of anything anyone else contributes, and actually learning something new?

(And, btw, if anything I've written above is incorrect, I would happily welcome correction from someone informed...unlike someone else we know in this thread)
THX is not any standard, it is a recommendation. In the days that THX was in the commercial cinema, after approving the reference levels and other criteria were met, they let the owner have a plaque over the cinema entrance that had the THX "certification" I have thrown plenty of those away. THX first appeared in theaters, in which their logo would show before the start of a film. Since THX was originally created for motion picture quality, the very first film to show THX was Return of the Jedi, in its theatrical debut on May 25, 1983. From there, THX began to appear before all movies from July 1, 1983, until August 30, 1997, when THX was no longer classified as a "motion picture sound system". At that point, THX had certified VHS/home video releases (as well as Laserdisc at the same time, and later DVDs, after 1998) beginning in 1995. Prior to September 1, 1997, no longer being known as a "sound system", THX was removed from all theaters.

The THX standard, reference volume level 6.5. That will take care of that A/C and squeaky wooden seats.

And here I was reading all of this stuff thinking that Home Theater projectors were made of super parts and pieces and could do anything a billion times better than the commercial units, only to have you tell me it only has 300:1 ANSI, that is 1000:1 lower than a bad DCP of a 2K B-movie horror flick.
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And the payoff is never certain: Some observers contend that a generation has already been trained to be content with the small screen.

Some servers can do non-encrypted playback to an A/V projector, but it's just a ridiculously expensive media player if you don't have a cinema projector.
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Darin, I and a lot of others will be there all three days. It might be easier to hash this out in person.
I don't know what day I will be there. And if it goes like it always does, I want know to the night or morning before, if at all. I can't say I will be there and not be able to make it that day. I should hopefully know something next week.

And the payoff is never certain: Some observers contend that a generation has already been trained to be content with the small screen.

Some servers can do non-encrypted playback to an A/V projector, but it's just a ridiculously expensive media player if you don't have a cinema projector.
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