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Discussion Starter · #1 ·
PART 1

Lcd monitor backlighted by lots of individually controllable leds.

That gives you 200k:1 in dynamic range
http://www.brightsidetech.com/products/dr37p.php


Thanks to the indvidual control of separate light soucres one small part of the picture can be very very bright and others can show fantastic shadow detail in the dark that is BLACK!


Can this be reached for projection?


1 dlp and lcos with laser light sources should be able to exhibit an insanly high sequential contrast ratio.

The APL sets a brightness that the light source delivers but the native contrast limitation makes the supposedly black portion of the picture non black.


there needs a second mechanism


2 In parts of the image there is too much light to block. Some mechanism will need to block more light locally. That is the job for the fourth panel.


However SEOS has a 4-panel lcos display that is greater than 40000:1 and upto 250000:1 have been observed. The checkerboard contrast is only 150:1. Is something missing from the 4-panel concept or is it just in execution?


PART 2

HDR will become a reality with computer displays. Games is what is going to use this. I expect brightness to increase more than what I expect a lower black level. Crts are already providing deep blacks. In computers a source format will emerge with a greater provision for brightness range. We should all wear a burglar outfit when playing so that our white shirt does not reflect that bright light source back on the screen hiding your enemy in the corner.


HDTV and hd-dvd are not equipped to handle an extreme brightness range. In these formats you have some 200+ levels to work with. There is only so much you can show using these levels.


D-cinema is 12 bit at the source. Here there is a greater chance to implement some HDR technoly. Could HDR technology be THE big difference between consumer sources and what you see at the cinema?
 

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As I noted in the other thread, these variable backlight displays are intended for still images. They have problems with motion. The ordinary white credit roll over a scene for example is not possible with this technology. The intended market is scientific research, not entertainment.


There is also a potential problem with computer games. The technology exploits the fact that hard black to white transitions don't occur in nature. Now in comoputer generated imagery, these unatural transitions are more the rule than the exception. And a change from hard black to hard white across a single pixel can't be done effectivily with the coarse variable backlight technology. You would need a pixel per pixel based backlight such as a plasma screen. LCD panel over a Plasma backlight? Hmmm.


Lasers with DLP and or LCOS is interesting but not reality yet.
 

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I have seen this display and it is simply stunning.


On the topic of HDR projection, it has been done for prototypes. One way to do it is to shine a (very bright hopefully) projector of any type through a separately controllable LCD panel.




Quote:
Originally Posted by Ohlson
PART 1

Lcd monitor backlighted by lots of individually controllable leds.

That gives you 200k:1 in dynamic range
http://www.brightsidetech.com/produ...dr37p_specs.pdf


Thanks to the indvidual control of separate light soucres one small part of the picture can be very very bright and others can show fantastic shadow detail in the dark that is BLACK!


Can this be reached for projection?


1 dlp and lcos with laser light sources should be able to exhibit an insanly high sequential contrast ratio.

The APL sets a brightness that the light source delivers but the native contrast limitation makes the supposedly black portion of the picture non black.


there needs a second mechanism


2 In parts of the image there is too much light to block. Some mechanism will need to block more light locally. That is the job for the fourth panel.


However SEOS has a 4-panel lcos display that is greater than 40000:1 and upto 250000:1 have been observed. The checkerboard contrast is only 150:1. Is something missing from the 4-panel concept or is it just in execution?


PART 2

HDR will become a reality with computer displays. Games is what is going to use this. I expect brightness to increase more than what I expect a lower black level. Crts are already providing deep blacks. In computers a source format will emerge with a greater provision for brightness range. We should all wear a burglar outfit when playing so that our white shirt does not reflect that bright light source back on the screen hiding your enemy in the corner.


HDTV and hd-dvd are not equipped to handle an extreme brightness range. In these formats you have some 200+ levels to work with. There is only so much you can show using these levels.


D-cinema is 12 bit at the source. Here there is a greater chance to implement some HDR technoly. Could HDR technology be THE big difference between consumer sources and what you see at the cinema?
 

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Quote:
Originally Posted by Ohlson
Lcd monitor backlighted by lots of individually controllable leds.

That gives you 200k:1 in dynamic range.
The number you quoted has no practical meaning as 99.99(9)% of video material is other than black.

However, it would be great for the "Finding Nemo" scene that goes totally "blank."

OTOH, the 25,000:1 ANSI contrast ratio (see the link below) IS great.

This is want I want from my projector...
http://www.brightsidetech.com/products/details.php


Btw., the link in the original post does not work. Here's the main page:
http://www.brightsidetech.com/


Mike
 

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I think this is the link Ohlson was referring to.
 

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Discussion Starter · #6 ·
The link is now working.


Glimmie

They are targetting Film/Post processing as well. Movies do consist of a series of still images. Is there a problem with this display apart from credits. If it can show photographs it should be able to show lots of photographs in rapid succession. It might help if the lcd portion of the display had higher native contrast.


Is not computer graphics on the verge of being powerful enough not to cheat, that is to look like reality without sharp transitions? The solution is to make the games look like reality without the sharp black to white transitions. Ps3 will be powerful enough to handle games that look like a hdtv version of reality.


alternatives in the future

1 scanning laser display, I would think the optimum would be to have a full color spot scan the screen, no convergence errror what so ever. One technology available uses this concept. The problem will be to get high enough resolutions practical. Microvision can scale resolution but they use separate rgb dots.


2 3-panel approach dlp or lcos with laser. Is it good enough when 5000:1 is reached in native contrast. Dlp is there now and lcos is at >3500-4000:1 so 5000:1 should be within reach.


3 4-panel approach would be more costly but could offer close to black->white single pixel transitions.
 

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What about the Sony Qualia 005, which is a 46" LCD monitor equipped with the "Triluminous" LED backlight system ?

They claim that is has a much wider color gamut than other LCDs due to the use of R/G/B LEDs for backlighting, but how would its use affect contrast and brightness ? Could we expect improvements on those parameters as well, simply because of the use of LEDs for backlighting ?

If i remember correctly the list price for the unit is around $12.000, at a time when comparable-sized LCD monitors from Sharp are now selling for $5.000....

As Glimmie pointed out, i doubt Sony's implementation of this backlighting type is on a "pixel-per-pixel" basis (cost/technology prohibitive ?), so i imagine all we can expect is a wider color gamut.....Hmm, all of that for the bargain price of $12.000 !

Well, it does have that magic name, QUALIA........
 

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Discussion Starter · #8 ·
The Qualia 005 controls the output from the rgb leds on a global level and less radically then the professional display above.


I will try to answer my own question. HDR will never be for large screen projection but restriced to smaller displays. It will be difficult to have superbright big screens. Mitsubishi is thinking of building LED screens for the cinema.


However there is still a chance that there will be HDR projection and I would spell it Microvision. They can scan your retina direcly and less energy is needed. I am sure a laser can provide real life brigtness to the retina as well as no light. The limitation will be in modulation speed and thus limit resulution. You will need many light sources to reach higher resolution. Microvision is working in that direction.
 

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Quote:
Originally Posted by Glimmie
And a change from hard black to hard white across a single pixel can't be done effectivily with the coarse variable backlight technology. You would need a pixel per pixel based backlight such as a plasma screen. LCD panel over a Plasma backlight? Hmmm.
The research seems to indicate that a low-res backlight is perceived as good enough because the scattering of light within the eye softens the transition much more than the low-res backlight does.
 

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Quote:
Originally Posted by Ohlson
However there is still a chance that there will be HDR projection and I would spell it Microvision. They can scan your retina direcly and less energy is needed. I am sure a laser can provide real life brigtness to the retina as well as no light. The limitation will be in modulation speed and thus limit resulution. You will need many light sources to reach higher resolution. Microvision is working in that direction.
And the best part is, if the scanning machanism ever fails, bingo, your cataracts are cured!


:D


Mike
 

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Quote:
Originally Posted by MikeSer
The number you quoted has no practical meaning as 99.99(9)% of video material is other than black.

However, it would be great for the "Finding Nemo" scene that goes totally "blank."

OTOH, the 25,000:1 ANSI contrast ratio (see the link below) IS great.
I'm not sure why you would be so happy about an ANSI CR that goes way beyond anything that anybody would need to be satisfied with our vision and not be at least as happy about the on/off CR that does not go beyond the capabilities of our vision. If you use this calculator to compare 200k:1 on/off CR and 25k:1 ANSI CR to 200k:1 on/off CR and just 1k:1 ANSI CR (while setting the room gain to 0) you will see that the instantaneous CRs hardly vary between those two. A checkerboard of 5 IRE and 0 IRE is 155:1 on the higher ANSI CR model while it is 135:1 on the lower ANSI CR model, but that isn't much difference because it is the on/off CR that is more the limiting factor even in this very dark image. In fact, if you compared a 100k:1 on/off and 25k:1 ANSI model to a 200k:1 on/off and 1k:1 ANSI model it is the first one that would have the lower instantaneous CR in that very dark (but not blackout) image and the differences up where both are above 500:1 instantaneous with a 4x4 checkerboard really don't matter all that much (at least to me) given the limitations of our eyes.


--Darin
 

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Quote:
Originally Posted by Erik Garci
The research seems to indicate that a low-res backlight is perceived as good enough because the scattering of light within the eye softens the transition much more than the low-res backlight does.
Yes in natural scenes. The problem is artificial scenes. Hence my credit roll example.
 

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Quote:
Originally Posted by Ohlson
The link is now working.


Glimmie

They are targetting Film/Post processing as well. Movies do consist of a series of still images. Is there a problem with this display apart from credits.
"Shrek", "Shark Tale", come to mind. These would be problematic for this display technology as it stands now.
 

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Quote:
Originally Posted by Glimmie
Yes in natural scenes. The problem is artificial scenes. Hence my credit roll example.
This seems like mostly a speed issue where they could fall back on closer to their native CRs in these scenes if they have to. Credit rolls cause washout outside the pixels that are on for most (maybe all) displays and it is a matter of degrees.


--Darin
 

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Quote:
Originally Posted by darinp2
This seems like mostly a speed issue where they could fall back on closer to their native CRs in these scenes if they have to. Credit rolls cause washout outside the pixels that are on for most (maybe all) displays and it is a matter of degrees.


--Darin
No, it's not a speed problem. LED's can switch in orders of magnitude faster than an LCD. It's the coarse grid of the backlight. If you need to make a large contrast step in the space of a few pixels, you can't do it. Yes, you can average out the backlight but then you are back to a plain old LCD. Now consider what happens if you need a large step for several seconds. You even out the back light and the whole image now loses contrast to the benefit of the the needed step area. It's going to look like a cheap CRT monitor with a sloppy or non-existant clamp circuit. The black level will wonder all over the place.


The technology is limited to natural photography. It also probably has great potential in scientific display applications like looking at cell structures. But for mainstream "television" like applications it has serious drawbacks.
 

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Glimmie - have you actually seen one of these functioning? While I am in complete agreement with your assessment that they are not able to provide pixel accurate brightness and contrast, they nonetheless do provide an enhanced image quality with everything I have seen displayed on them (I have seen the prototypes twice last year when it was under the name sunnybrook technologies, and the new product at SIGGRAPH last week).


One poor choice on their part, however: They neglected to color calibrate their reference and modified displays for the show floor, doing only basic white and black level adjustment, so while you could see the benefits of their process in increased contrast, their unit's colors had a somewhat washed out look by comparison.


As far as Sony's LED backlit monitor, NEC is now shipping their equivalent product and the colors are indeed quite stunning compared to CCFL lit LCDs. I doubt they or Sony will be using the technique Brightside uses however, as it is pretty well patented and the person at NEC'S booth admitted this was an issue in doing so. So their monitor remains at a traditional 500:1 CR.


BB
 

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Quote:
Originally Posted by Brandon B
Glimmie - have you actually seen one of these functioning? BB
I didn't make it to Siggraph but let me guess. Was it the "babbling brook across the open meadow" picture?


Yes I have seen it several times over the past two years in private demos. It does produce an image like I have never seen before. My point is that it simply doesn't work for entertainment film and video as it stands now.
 

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They were running video on it this time. Although, not CGI or stuff that would exhibit the problems you point out (even though it was SIGGRAPH). And only $47K for 42" LCD screen.


BB
 

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Discussion Starter · #19 ·
darinp2

What do you make of the fact about the 4-panel lcos digital projection monitor with 40000:1 (and possibly even 250000:1) but only 150:1 ANSI cr?


Lets think about if the same system as above was compared with a traditional 3-panel design for


A 32x32 checkerboard 10 IRE to 0


Do you expect a 4-panel design to show its virtues in such a comparison?


Brandon B

I wonder if there will be any develpment in lcd monitor contrast coming? Could we see something similar to Bi:NA 6 and Crystal clear fine but for lcd displays? That way a LEDs+lcd monitor could work even better.
 

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I think a crude, WVGA DMD coupled with a 3-chip LCOS would be wonderful.
 
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