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post #1 of 111 Old 06-30-2004, 06:10 AM - Thread Starter
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I’ve rearranged this post - since most people who visit are probably just coming to see the updates. I’ve moved the table to the top. Effective July ‘04 Home Theater magazine implemented a new process for measuring contrast ratio. Finally there is an independent process that should give the potential buyer a better idea as to the brands true contrast ratio. This table holds the results. To learn more about the process read the section below the table. Category leader(s) shown in red.

Code:

                  Brightness   Black Level Contrast  ANSI            Date
Brand/ Model      100-IRE wht  0-IRE Blk   Ratio     Contrast  MFG   Reviewed
Tested              (ft-L)     (ft-L)     (xxxx:1)  (xxx:1)    CR    (mmm,yr)
--------------    -----------  ---------  --------  --------  ----  --------
Plasma
Mitsubishi PD6130    12.51      0.129         97       173    1200   AUG 2004
Vidikron VP-50       17.8       0.115        155       268      ?    OCT 2004
Panasonic TH42PX25   21.95 (40) 0.027        813       780    3000   NOV 2004
LG RU-42PX11         27.8  (69) 0.069        403       385    5000   FEB 2005
Panasonic TH42PD25   18.64 (31) 0.023        810       998    4000   FEB 2005
Vinc P42HD           20.22 (57) 0.088        230       464    3000   FEB 2005
LG 42PX4D            25.32 (72) 0.027        938      1327    5000   AUG 2005
Panasonic TH42PX500U 21.03 (55) 0.027        779       364    3000   DEC 2005
Pioneer PDP-5060HD   20.16 (61) 0.033        611      1135    4000   JAN 2006
Philips 42PF9630A    24.2  (53) 0.015       1613      1108   10000   JAN 2006
Hitachi 42HDT52      19.22      0.043        447       360           FEB 2006
Fujitsu P50XTA51UB   18.03 (56) 0.035        515       786           OCT 2006
Panasonic TH42PX60U  27.77 (49) 0.012       2314       740   10000   NOV 2006
Pioneer PRO FHD1     17.75 (44) 0.032        550       930    3000   website
Pioneer PRO-940HD    18.55 (53) 0.039        476       851           MAR 2007
Hitachi P42H401      21.74 (57) 0.084        259       414           AUG 2007
Panasonic TH42PZ700U 20.2  (58) 0.015       1347      1182    5000   SEP 2007
Panasonic TH50PZ700U 16.47 (44) 0.017        969      1022    5000   SEP 2007
Pioneer PRO-110FD    16.08 (43) 0.004      4020(10645)3239    KURO   DEC 2007

Note: LCD testing usually shows best contrast ratio with lowest backlight setting.
If reported the max. brightness or deepest black w/resulting (CR) is shown in brackets.

                  Brightness   Black Level Contrast  ANSI            Date
Brand/ Model      100-IRE wht  0-IRE Blk   Ratio     Contrast  MFG   Reviewed
Tested              (ft-L)     (ft-L)     (xxxx:1)  (xxx:1)    CR    (mmm,yr)
--------------    -----------  ---------  --------  --------  ----  --------
LCD (Flat Panel)
Hitachi 32HDL51      19.78 (88) 0.037        535        546    900   APR 2005
Samsung LTP468W      63.05      0.161        392        378    800   APR 2005
Viewsonic N3200w    161.00      0.294        548        511    600   APR 2005
Sharp LC-45GX6U      24.75(124) 0.049(.258)  505 (480)  442    800   JUN 2005
LG 42LP1D           142.0       0.147        966        473   1200   AUG 2005
NuVision NVX32HDU    85.77(118) 0.142(.197)  604 (600)  586   1000   SEP 2005
Philips 32PF9996     99.08      0.185        536        505    800   OCT 2005
JVC LT-32X776        70.62(104) 0.122(.186)  579 (558)  493    800   OCT 2005
Proton LX-32B1C2     72.06(161) 0.104(.234)  693 (687)  686    550   OCT 2005
Nikada LA1371       175.4       0.296        593        548    500   OCT 2005
Mitsubishi LT-4260   58.16(151) 0.103(.292)  565 (517)  547    800   OCT 2005
Sony KDL-V40XBR1     55.6 (134) 0.047(.126) 1183(1062)  976   1300   JAN 2006
Maxent MX-26X3      128.5       0.169        760        725    800   JAN 2006
Toshiba 32HLX95     103.0  (41) 0.160(.064)  644 (633)  535    800   MAR 2006
WestinghouseLVM-42w2 57.19(158) 0.064(.192)  894 (825)  712   1000   MAY 2006
Sony KDL-40S2000     79.14(141) 0.066(.119) 1199(1187) 1078   1300   JUN 2006
Hitachi 32HLX61      23.99 (94) 0.036(.171)  666 (548)  517          JUN 2006
Sharp LC37D40U       17.76(122) 0.014(.118) 1269(1034)  768   1200   JUN 2006
Sharp LC57D90U       58.43 (99) 0.045(.079) 1298(1252) 1065   1500   AUG 2006
                           (28)      (.022) 1289
Samsung LN-3251D     41.15(138) 0.032(.120) 1286(1152) 1098   4000   SEP 2006
JVC LT-37X987        45.17(101) 0.062(.143)  729(709)   669    800   NOV 2006
Philips 42PF9831D   165.3       0.089       1857        689   4500   DEC 2006
Vizio GV42L         160.9 (38)  0.208(.052)  774(730)   797          JAN 2007
Toshiba 42LX196     124.5 (34)  0.178(.049)  699(685)   625          JAN 2007
Sony KDL46XBR2      127.5 (23)  0.091(.018) 1401(1303) 1217          JAN 2007
HP SLC3760N          89.7(151)  0.084(.143) 1068(1057)  967          MAR 2007
WinBook 40D1        125.2 (61)  0.082(.042) 1527(1457) 1226          APR 2007
Mitsubishi LT37132  134.9 (31)  0.115(.027) 1173(1150) 1077          MAY 2007
NEC Multeous M40     45.58(125) 0.041(.128) 1112(981)   922          MAY 2007
Olevia 747i         134.5 (73)  0.139(.076)  968(965)   825          MAY 2007
Sharp LC-52D92U      14.09(93)  0.006(.046) 2348(2022) 1968          JUL 2007
Samsung LN-T5265F    19.63(106) 0.017(.105) 1155(1005) 1142          OCT 2007
JVC LT-47X788       113.7       0.01       11370       1753          NOV 2007
Philips 47PFL9732D   14.5(55)   0.023(.121)  630        493          DEC 2007
Sony KDL-46XBR4     120 (22/47) 0.007(.005)17143(4to9k)1687          DEC 2007
Toshiba 52LX177      21.08(120) 0.011(.091) 1916(1320)  980          DEC 2007
Samsung LN-T5271F    63.14(20)  0.012(.010) 5262(1776) 1413          DEC 2007

                  Brightness   Black Level Contrast ANSI            Date
Brand/ Model      100-IRE wht  0-IRE Blk   Ratio    Contrast  MFG   Reviewed
Tested              (ft-L)     (ft-L)     (xxxx:1)  (xxx:1)   CR    (mmm,yr)
--------------    -----------  ---------  --------  --------  ----  --------
DLP Projectors
InFocus 7205         22.37       0.022       1017       355   2200   JUL 2004
Marantz VP-12S3       8.514      0.003       2838       503   3800   JUL 2004
Sharp XV-Z12000       6.85       0.002       3425       424   5500   JUL 2004
Yamaha DPX-1100       9.351      0.002       4676       510   4000** MAR 2005
Samsung SP-H700AE    20.83       0.014       1488       370   2800   MAY 2005
InFocus 7210         25.62       0.018       1423       419   2800   JUL 2005
Sharp XV-Z12000 MII   7.263(22)  0.002(.016) 3632(1381) 525          MAR 2006
Yamaha DPX-1300       6.8  (18)  0.002(.009) 3400(2000) 527          JUL 2006
Sharp XV-Z20000       9.117(29)  0.001(.015) 9117(1933) 606          MAR 2007

Midrange Projectors
Panasonic PTAE700LCD 13.5        0.019        711       161   2000   MAR 2005
Sony VPL HS51 LCD     7.701      0.003       2567       162   6000   MAR 2005
Hitachi PJ-TX100 LCD  4.905(20)  0.006(.029)  818(696)  118          OCT 2005
Viewsonic Cine5000   21.7  (16)  0.017(.013) 1276(1265) 231          MAR 2007


Budget projectors
BenQ PB6200 DLP      14.48      0.021         690       283   2000   SEP 2004
Epson PL Home 10+    11.6       0.015         773       249    800   SEP 2004
Optoma H30 DLP        9.426     0.011         857       240   2000   SEP 2004
Mitsubishi HC900 DLP  8.401     0.005        1680       417   4000***MAR 2005
Optoma H27 DLP        8.785(11) 0.005(.007)  1757(1594) 455          OCT 2005
Epson PL Cinema 550  11.78 (28) 0.003(.06)   3927(481)  168          MAR 2006
Optoma HD72 S+DLP    9.855  (7) 0.012(.009)   821(770)  395          MAY 2006

1080p LCOS/SXRD/LCD projectors  
Sony VPL-VW100       15.18      0.001      15180        251   RUBY   APR 2006
JVC DLA-HD1          15.56      0.001      15560        250          JUN 2007
Mitsubishi HC5000LCD 11.2(15.5) 0.002(.003) 5600(5160)  206          JUN 2007
Sony VPL-VW50 SXRD   17.05(17.8)0.002(.009) 8525(1968)  231   PEARL  JUN 2007
Epson Powerlite1080p  6.852(9)  0.001(.002) 6852(4497)  211          JUL 2007

Sony VPL-VW60                                               BLK PEARL

                  Brightness   Black Level Contrast ANSI            Date
Brand/ Model      100-IRE wht  0-IRE Blk   Ratio    Contrast  MFG   Reviewed
Tested              (ft-L)     (ft-L)     (xxxx:1)  (xxx:1)   CR    (mmm,yr)
--------------    -----------  ---------  --------  --------  ----  --------
LCOS/SXRD Rear Projection
JVC HD61Z575 D-ILA  165.8      0.215         771     136       ?     DEC 2004
JVC HD70G886 D-ILA  130.1      0.14          929     110       ?     SEP 2005
Sony KDS-R60XBR1     93.31     0.007       13330     297     10000   NOV 2005
Sony KDS-R50XBR1    142.3      0.021        6776     294             FEB 2006
JVC HD56FH96 D-ILA   91.04     0.058        1570     208             FEB 2006
Sony KDS-60A2000     63.19(83) 0.008        7899     270             OCT 2006
Sony KDSR60XBR2     130.9      0.009       14544     364             FEB 2007

Rear Projection
Sharp DLP 56DR650    83.69     0.080        1046     286             OCT 2005
SamsungDLP HLR5668W 137.2      0.018        7622     374             FEB 2006
HP DLP MH6580n      104.4      0.015        6960     410             FEB 2006
Mitsubishi DLP52628 133.6      0.030        4453     416             FEB 2006
Toshiba 62MX195     100.1      0.025        4004     307             FEB 2006
Samsung HLS5679W    107        0.090        1189     226             JAN 2007
JVC HD-61FN97        98.09     0.016        6131     182             FEB 2007
Mitsubishi WD65731   98.72     0.127         777     385             FEB 2007
Olevia 565H         135.8      0.035        3880     338             FEB 2007
Samsung HLS6188W    169.7      0.033        5142     561             FEB 2007
Toshiba 62MX196      65.09     0.022        2959     401             FEB 2007
NuVision 52LED DLP  125        0.085        1471     423             APR 2007

Cathode Ray Tube (CRT)
Toshiba 34HF84       15.32    <0.001*     >15320     135             JAN 2005

* actually may have been lower - but that was the bottom of their test
   equipment scale.
** white boost fully on, iris fully on, 2000 white boost on, iris Off
*** 4000:1 (with Cine Focus close) 2000:1 (with Cine Focus open)

The Contrast Ratio in the above table is a calculated value.
It is determined as follows: 100-IRE white / 0-IRE Black.
How they determined the ANSI Contrast value is described below.

Here is an excerpt (partially edited) from the original article that describes what they are doing.

"A New HT Measurement: Contrast Ratio
Believe it or not, contrast ratio is not the only thing you need to know about purchasing a TV. Like any measurement it shouldn't be taken alone; in many cases it shouldn't be taken at all. The human eye can, at best, discern a contrast ratio of a few hundred to one. So, even a display with a claimed 800:1 contrast ratio has more than enough contrast to appease the eye. There's more to it than that, but that's a discussion for another article.
So what's with a contrast ratio of 2000:1 or even 3000:1? Well it's misleading at best and a lie at worst. Unlike most product stats, there's no regulation for how a company measures a display's contrast ratio. One company could measure a full-white field versus a 0-IRE signal, while another company could use a 100-IRE window versus no signal at all. The American National Standards Institute (ANSI) has defined one relatively reasonable method that many manufacturers use, but it is by no means mandatory.
From this point on in our display reviews we're going to cut through all that and offer you a series of measurements consisting of contrast ratio, lowest and highest light level, and ANSI contrast all in one section. Don't worry, we'll still include the color temperature and color gamut graphs we've given you all along.

Decoding the New Measurements
For our reviews, we will define contrast ratio as the ratio of light level produced by a 100-IRE full field divided by the light level produced by a 0-IRE full field. The number inside the black box is the total light output (in foot-lamberts) that the display produces when supplied with a 0-IRE signal from a DVD. This represents the darkest the display will get when it's active and fed a signal, it should be as close to zero as possible. With projectors we use a Da-Lite Da-Mat 1.0 gain screen that measures 87 by 49 inches (93 inches diagonal). If a display has good DC restoration, the measured black level will be similar to the black level the display produces when there's other video material on the screen.
The number in the white box is the display's total light output when displaying a full-white (100-IRE) field in the same mode that produces the listed black level. (The mode chosen will be the one with the best contrast ratio), Now I'll be the first to tell you that a full-white field almost never happens in actual source material (for that matter neither does a full-black field) for this though it's what we're going to use. Why? Because we have to use a full-black field (a black window just wouldn't work), and this is its true opposite.
Doing the measurement this way is like testing an amp's maximum power output: it may not reflect the most real world scenario, but it does five an overall view of the device's output.
Using a full-white field will affect plasmas the most, as they are built to have less light output on a full field compared with a 100-IRE window. If there's a difference between the windowed measurement and the full screen, we'll list it in the measurement text.
ANSI measures the contrast ratio using a 16-box checkerboard pattern on the screen, so we'll do that, too. This is done by dividing the average level of the eight white boxes by the average level of the eight black boxes.
If a display has different settings that affect contrast ratio, we will test all of them and use the best one for both contrast-ratio measurement tests. Most importantly all contrast-ratio measurements will be done after the display is fully calibrated to as close to D6500 as it can be.
To conduct these tests, we're using a Konica/Minolta LS-100 light meter, the most accurate tool for the job. We're still be using our Photo Research PR-650 spectoradiometer for color temperature and color measurement."

Note: The mode discussed above, at least in relation these early results on projectors, was described to be high power lamp mode.
What's even more interesting in examining the differences in the numbers in the above table (for DLP HD2 -only) - is that all these projectors use the identical HD2+ chip!

Their final comments:
(this commentary was made at the process inception when only the three DLP HD+ models had been tested)
"So which one would I pick? Well that's easy. I'll take the Marantz's optics, case, and color points; the Sharp's black level and adjustable iris, and the InFocus overall light output and price."

See it's easy to purchase your TV based on the specs!

And for the metric folks:
Luminance - refers to the amount of visually effective light emitted by an extended source. Typically expressed in nits, footlamberts (fL) or candelas per square meter (cd/m2).
One fL = 3.43 cd/m2 or 3.43 nits
One cd/m2 (1 nit) = 0.292fL

Other pertinent data
Here’s some tests performed by primediabusiness associated with Peter Putman a well respected independent consultant. You can learn more by going here
Note the Brightness measurements are in nits as opposed to those shown in the above table.

Code:

                  Black  Brightness  Brightness  4:3 ANSI  4:3 Peak  16:9 ANSI  16:9 Peak  
Brand/ Model      Level  4:3 white   16:9 white  Contrast  Contrast  Contrast   Contrast
Tested            (nits)   (nits)    (nits)      (xxx:1)   (xxx:1)    (xxx:1)   (xxx:1)
--------------    ------ -----------  ---------  --------  --------   --------   --------
LCD’s
Barco Solaris LC40M 1.25              244.65                              190      204
LG L4200A           2.6               219.9                                61       73
NEC LCD 4000        *      319.88     330.85        129       152         136      169

Plasma’s
Hitachi CMP4201U    0.39    83.28      67.21        257       327         284      413
NEC PS42VP4         0.34    72.92      59.98        386       457         332      389
NEC PX-61MX2A       0.56               52.56                              200      358
Panasonic TH42PWD6  0.2     69.13      55.13        488       604         508      649
Philips 32FD9954            71.85      54.34        159       188         134      157
Pioneer PDP-504MX   0.54               57.5                               146      208
Sony PFM-42X1       0.18               95.13                              648     2007
Vizio P4                      -        78.32        271       291         198      224

* mentioned to be much higher than NEC plasma, but numbers not provided in article.

And here’s some more data courtesy of PC Magazine this article attachment.
Code:
                         Avg.     Avg
                         Black    White     Average
Brand/                   Level    Level     Contrast  
Model  Tested            (nits)   (nits)    (xxx:1)   
-------------------      ------   --------  -------
LCD’s
Samsung LT-P468W           0.57     237       422
Sharp Aquos LC-37G4U       0.74     322       437
Syntax Olevia LT30HV       0.77     415       541

Plasma’s
Fujitsu P55XHA30WS         0.39     109       278
Panasonic TH-50PX25U/P     0.15      87       583
Pioneer Elite Pro 1110HD   0.45     122       269

Rear Projection
JVC HD-61Z575 HD-ILA       2.20     225       104
Samsung HL-P5063W          1.03     174       174
Sony GW KDF-60XBR950       1.24     165       137



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post #2 of 111 Old 06-30-2004, 10:04 AM
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Quote:


Originally posted by semigolfer
The human eye can, at best, discern a contrast raio of a few hundred to one. So, even a display with a claimed 800:1 contrast ratio has more than enough contrast to appease the eye. There's more to it than that, but that's a discussion for another article.
So what's with a contrast ratio of 2000:1 or even 3000:1? Well it's misleading at best and a lie at worst.

I read this too. Either this person understands things fairly well and just happened to write something very misleading but would save the real part for "a discussion for another article" or they took a little bit of information and didn't know how to apply it. The human eye can discern a contrast ratio of some small amount at one time. It can discern huge contrast ratios (I believe a million to one or more) over multiple images and this is mostly what on/off contrast ratio is about. Movies have both bright scenes and dark scenes, not just mixed scenes. The amount that a person can see at any one time with about equal amounts of black and white is more relevant to the ANSI CR test. Both tests are important as the ANSI CR test pretty much defines the washout effect and the on/off test defines the floor.

And people keep quoting numbers about what a person can see at one time with equal mixes as if this is all the CR we need. In real world video people are allowed to look wherever they want and I've done some testing with an image that was 3-5% white, then projector black, then room reflection black on my screen and then screen masking black (I've just described what dominates each area as everyone of them is a mixture of multiple sources of light). I can make each of these out even though the white to projector black was about 1600:1 (with a large margin of error), the white ellipse to room reflection black was probably 5k:1 or more and then it went way up to the screen masking and velvet around the screen. This was on a screen about 8' wide from about 13' back in a light controlled room. I would definitely have been able to tell if that 1600:1 area had been improved to something like 20k:1.

Plasmas putting out less ft-lamberts for full field white than windowed white is very similar to CRTs.

--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."
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post #3 of 111 Old 06-30-2004, 10:39 AM
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Originally posted by darinp2
The human eye can discern a contrast ratio of some small amount at one time. It can discern huge contrast ratios (I believe a million to one or more) over multiple images and this is mostly what on/off contrast ratio is about.
--Darin

Here are the scientifically proven numbers
------------------------------------------------------------
The dynamic range of the human eye is .0001 to 10,000 or in other words 100,000,000 to 1 (7 decades).

The contrast ability of the human eye in daylight conditions is 1% or in other words 100:1

The contrast ability of the human eye in dark/dim conditions is 10% or in other word 10:1
-------------------------------------------------------------

In other words, the eye has a very large dynamic range but for a given luminence the contrast sensitivity (ability to discern luminence values) is very small!!!! and it changes with luminence. The lower the luminence the lower the sensitivity.


Cheers

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post #4 of 111 Old 06-30-2004, 11:18 AM
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Originally posted by xrox
Here are the scientifically proven numbers
...
The contrast ability of the human eye in daylight conditions is 1% or in other words 100:1.

In other words, the eye has a very large dynamic range but for a given luminence the contrast sensitivity (ability to discern luminence values) is very small!!!! and it changes with luminence. The lower the luminence the lower the sensitivity.

I think it depends on what you use as "discern luminance values". A person doesn't have to be able to tell you what an exact luminance value is in order to see an improvement. For instance, if you put up a small white ellipse (like I did in my example) on a dark background of either 1000:1 instantaneous CR or 20k:1 instantaneous CR I guarantee you I could tell you which was which after leaving the room and coming back in. In the first case I would not mistake the background for true black and in the second case it would be much closer or I would mistake it for true black. That doesn't mean I could tell you what the background luminance is with a small margin of error, but I can sure tell you that it isn't black in one case. Going from 100:1 to 20k:1 instantaneous in images like the one I described would be a night and day difference in a dark room. So, using these 1% and 10% numbers to justify lower design thresholds in video display equipment is just incorrect, IMO.

In other words, a video display with a design that can go way beyond these 1% and 10% thresholds in images like the one I described will show differences to the human eye.

As I mentioned, in video people are not forced to look at one spot. They can choose where to look on the screen and this definitely applies to front projection where many sit at close to 1.5x in dark rooms. For bright rooms like where many people watch plasmas it is a different story.

--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."
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post #5 of 111 Old 06-30-2004, 11:23 AM
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Quote:


Originally posted by xrox
In other words, the eye has a very large dynamic range but for a given luminence the contrast sensitivity (ability to discern luminence values) is very small!!!! and it changes with luminence. The lower the luminence the lower the sensitivity.


It's also dependent on spatial frequency of the pattern. I posted a chart and some references here. Darin was going to read the big thick paper and tell us all about it
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post #6 of 111 Old 06-30-2004, 11:39 AM - Thread Starter
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Boy - you guys are over the post like cats on spilt milk. I agree with both of your responses. They add considerable information to this discussion. As the nuances of contrast ratio make it NOT the most straightforward spec to understand. It was even interesting to note on their proposed procedure that Home Theater Magazines measured and then calculated contrast ratio (100-IRE)/(0-IRE) rank ordered these projectors differently than the ANSI Contrast Ratio.

Although I'm not an expert in this matter I've done a considerable amount of reading on this subject trying to understand the value of this spec, when it comes to buying a TV. A couple of interesting things I've read include:
"The goal of any televion technology is to deliver a picture that looks as film-like as possible,"" Film has a contrast ratio closer to 10,000-to-1, but 4,000-to-1 is close enough to fool the human eye."

All of this has led me to believe that when I do get around to buying a TV, it will be my eyes that make my decision. But my eyes will view the competing brands, in different ambient lighting conditions, while viewing movies shot in different lighting conditions, - as many of the experts here in the AVS forum have long proposed.

What I was most interested in and the reason I posted was that - finally a trade publication was going to finally clarify how they were going to measure contrast ratio in the future, and why they were making these choices. Thus finally an "independent" source, who does a lot of reviews, would provide what appears to be most objective results than I had seen to date regarding CR.
And I thought the initial numbers were quite interesting considering the manufacturers started their designs with the same chip.



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post #7 of 111 Old 06-30-2004, 12:05 PM
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Quote:


Originally posted by wjchan
It's also dependent on spatial frequency of the pattern. I posted a chart and some references here. Darin was going to read the big thick paper and tell us all about it

Just what you posted is good stuff. The part that I think relates most to what I am saying is:
Quote:


One complicating factor is that, dependent upon light scattering into the fovea, the eye can have partial local adaptation to features in an image to increase sensitivity.

The Contrast Sensitivity Function (CSF) of the HVS is a measure of the ability to discriminate small luminance changes in a sine wave pattern target on a uniform background.

This "complicating factor" definitely relates to watching a large image in a dark room. And this CSF is a measure of the ability to discriminate small luminance changes. Anybody who designs a display device who uses this as an excuse to have performance that will be noticably substandard when the luminance changes aren't small is misapplying the results.

From the things I've read contrast ratio is one of the most misunderstood things. I relate the general opinion within much of the projection community (including professional writers) that on/off contrast ratio doesn't matter to the old flat earth theory. They are just plain wrong and they've used information about instantaneous contrast ratio without understanding things. Greg Rogers from WideScreenReview is the only writer I can think of who I know really gets this stuff. I don't claim to understand it all, but there is a big jump from some of these guys who disclaim any kind of on/off contrast ratio as relevant and having a clue.

At least in this case they still published some numbers. I still find it funny how they take a black level reading of 0.002 with a device that is only accurate to either plus or minus 1 or 2 in the last digit and then claim 4 digits of precision in their CR number, though.

--Darin

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post #8 of 111 Old 06-30-2004, 12:17 PM
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darinp2,

on/off (dark room) contrast which most plasma displays quote (ie 3000:1 or whatever) is a direct measure of dynamic range and should be taken as such.

So for the average consumer an on/off contrast ratio of thousands:1 tells you two important things,

1) - the display has a fairly large dynamic range (ie large number of distinguishable/measurable luminance values are possible)
2) - the display has a fairly low black level (unless it is ungodly bright)

would you agree?

cheers

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post #9 of 111 Old 06-30-2004, 02:37 PM
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Quote:


Originally posted by xrox
on/off (dark room) contrast which most plasma displays quote (ie 3000:1 or whatever) is a direct measure of dynamic range and should be taken as such.

So for the average consumer an on/off contrast ratio of thousands:1 tells you two important things,

1) - the display has a fairly large dynamic range (ie large number of distinguishable/measurable luminance values are possible)
2) - the display has a fairly low black level (unless it is ungodly bright)

would you agree?

Yes, I would say that's pretty much true as long as the number you get is a real number and not just a marketing number. The on/off CR does only really tell you the endpoints and it is theoretically possible for a display to have a large on/off CR and only two levels total, but the on/off CR gives you the ratio of those endpoints and can be used with white levels (like ANSI lumens) to determine both points. In practice many of the displays we compare to each other have the same number of distinguishable luminance values (might be limited by 8 bits), but the higher on/off CR projector just has a bigger ratio for the endpoints.

With plasmas they could probably just give you the white level and the black level instead of the CR (although I don't know all the controls in plasmas and how they interact). The difference with front projectors where I spend most of my energy is that the user has a lot of choices about how to use that CR with different screens sizes, screen materials, filters, etc. That is, if the front projector owner doesn't mind getting some ridiculously low white level (like 2 ft-lamberts) they can get a much lower black level with the same CR. I'm guessing that isn't true with plasmas.

--Darin

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post #10 of 111 Old 06-30-2004, 03:17 PM - Thread Starter
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Well my Aug 2004 issue of Home Theater Magazine arrived in the mail today - the first plasma CR data is now available. It's for a Mitsubishi PD-6130 61" plasma. It's been added to the table in the original post at the top of this thread.



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post #11 of 111 Old 06-30-2004, 03:34 PM
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Quote:


Originally posted by semigolfer
Well my Aug 2004 issue of Home Theater Magazine arrived in the mail today - the first plasma CR data is now available. It's for a Mitsubishi PD-6130 61" plasma. It's been added to the table in the original post at the top of this thread.

Wow, that is amazing. An ANSI CR higher than the on/off CR. This really wouldn't happen with projectors and I find it amazing that it would happen with a plasma, even with the ability to have higher ft-lamberts for white parts with less than full-screen white. It looks to me like the washout effect from white squares in the ANSI test to the black squares is almost negligable compared to the black level in the on/off test. Then the reason for the higher ANSI would be that the white squares are much higher than 12.51 ft-lamberts during the ANSI CR test. That is the only explanation I can think of unless there is something really funky in their control and they can go darker in the ANSI test than in the on/off test. That 97:1 actual vs 1200:1 spec sure is amazing too.

--Darin

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post #12 of 111 Old 08-16-2004, 04:24 PM - Thread Starter
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Sept 2004 HTMag has hit the mailbox.

Unfortunately no flat screens tested - just Budget Projectors - the post at the top of the thread has been updated. Maybe next month!



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post #13 of 111 Old 08-16-2004, 04:39 PM
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"Wow, that is amazing. An ANSI CR higher than the on/off CR."

So amazing, it tells you the test is inherently flawed.

" Using a full-white field will affect plasmas the most, as they are built ot have less light output on a full field compared with a 100-IRE window. If there's a difference between the windowed measurement and the full screen, we'll list it in the measurement text."

Right, so the Mitsubishi was "dialing back" the white field in all likelihood. Now, what were the black level and white level for the "window test". That would tell us something a bit more useful. We rarely ask our displays to light up full white -- nearly full blue or green are much more likely.

mark

There is no difference in HDMI cables. If you can see the picture without visible dropouts or sparklies, the cable is working at 100%. No other cable will display a better version of that picture. You're simply wrong if you think there is a better digital cable than one that is already working. (Oh, and plasma didn't die because of logistics problems, nor does OLED ship in big boxes because it comes from Korea.)
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post #14 of 111 Old 09-10-2004, 09:42 AM - Thread Starter
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Oct 2004 Home Theater Magazine arrives today.

They tested another plasma using their new contrast ratio measurement procedure, unfortunately this plasma also not very mainstream.

Results at the top of the thread.



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post #15 of 111 Old 10-09-2004, 12:51 PM - Thread Starter
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Nov 2004 Home Theater magazine just arrived.

Model tested, using their new contrast testing procedures: Panasonic TH-42PX25

Results added at top of thread - just like everyone has been saying Panny just knows how to make black better than the rest of the pack - but it's nice to see more independent confirmation.

Looking to purchase a flat screen - the same issue lists 400 models (LCD & plasma).



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post #16 of 111 Old 10-16-2004, 11:31 AM
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Are those numbers for real? If so, I want a Sharp XV-Z12000. How come I don't hear more about it in the $3500 FP forum? Does it have other problems?

Greg
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post #17 of 111 Old 10-16-2004, 11:39 AM
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The ANSI on the Panasonic is nothing short of stunning. The Marantz S3 and Sharp 12K are both terrific ANSI performers and to see a plasma so resoundingly beat them says a lot.

Mark

There is no difference in HDMI cables. If you can see the picture without visible dropouts or sparklies, the cable is working at 100%. No other cable will display a better version of that picture. You're simply wrong if you think there is a better digital cable than one that is already working. (Oh, and plasma didn't die because of logistics problems, nor does OLED ship in big boxes because it comes from Korea.)
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post #18 of 111 Old 11-16-2004, 05:29 AM - Thread Starter
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Dec 2004 Home Theater magazine arrived yesterday.

And they added an LCOS projection set to the list of models tested (using their new contrast ratio procedures) - the JVC HD-61Z575.

Hopefully a direct view LCD is coming up soon for testing, but I wonder if the results will tilt toward those found for this LCOS unit?
(i.e. high brightness (but probably not this high) - so-so blacks (but probably better than LCOS), a relatively high computed contrast ratio, but a mediocre ANSI result)



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post #19 of 111 Old 11-16-2004, 05:38 AM - Thread Starter
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Quote:


Originally posted by rogo
"Wow, that is amazing. An ANSI CR higher than the on/off CR."
So amazing, it tells you the test is inherently flawed.

" Using a full-white field will affect plasmas the most, as they are built ot have less light output on a full field compared with a 100-IRE window. If there's a difference between the windowed measurement and the full screen, we'll list it in the measurement text."

Right, so the Mitsubishi was "dialing back" the white field in all likelihood. Now, what were the black level and white level for the "window test". That would tell us something a bit more useful. We rarely ask our displays to light up full white -- nearly full blue or green are much more likely.

mark

Sorry for the late response here (only three months late ) - but recently I reread the article, and the author did state that:
"On a 100-IRE window, the PD-6130 was capable of 27.55 ft-L (it's normal for a plasma to have more light output on a window versus a full field)" and in the body of the article (as opposed to the HT Lab Measures section where I extract most of the above data) he also noted that the screen brightness was quite high, measuring 51.4 ft-L "at full contrast" on a 100-IRE window." And again in the body of the article - "The PD-6130 black level measured a mere 0.06 ft-L on a 0-IRE window, low enough to provide an excellent viewing experience with the room lights turned down or off."



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post #20 of 111 Old 01-05-2005, 11:33 AM - Thread Starter
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Another nice bonanza - three budget plasmas (VInc, LG, and Panasonic) were entered into the chart this month as they were reviewed in the Feb 2005 issue, which arrived in my mail today..

I also forgot to mention, I contacted the magazine about two months ago, asking that they consider testing some flat panel LCD models. They were kind enough to respond that they have four models under test, and they are scheduled for the April 05 issue. So we should get something in early March.



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post #21 of 111 Old 03-08-2005, 08:46 AM - Thread Starter
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Interesting, very interesting.

The April '05 issue of HT Mag arrived with today's mail and they tested three LCD panels - the first ones they've done with their next contrast testing protocals.
The results are in the table at the top of the thread.

I should probably also include these notes from the review of the Hitachi - since the results were somewhat unusual :
"The best contrast ratio was achieved in the night setting and the back light set for 0%. The brightest image was achieved in the day setting with the backlight set at 100%, which produced 87.5 ft-L with a 100 IRE window."



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post #22 of 111 Old 05-09-2005, 10:07 AM - Thread Starter
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The June 2005 issue of Home Theater Magazine has a review of Sharp's AQUOS LC-45GX6U.

The contrast results have been entered into the table at the top of this thread.
Also should note that 33 step (i.e. adjustable) backlight which really helped it's black level performance.



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post #23 of 111 Old 05-12-2005, 09:49 AM
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Bump for some great info and a question.

Is there any way to relate the light output on a 0 IRE window to a shade of grey?

ss
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post #24 of 111 Old 05-12-2005, 11:11 AM
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Quote:


Originally posted by xrox
Here are the scientifically proven numbers
------------------------------------------------------------
The dynamic range of the human eye is .0001 to 10,000 or in other words 100,000,000 to 1 (7 decades).

The contrast ability of the human eye in daylight conditions is 1% or in other words 100:1

The contrast ability of the human eye in dark/dim conditions is 10% or in other word 10:1
-------------------------------------------------------------

In other words, the eye has a very large dynamic range but for a given luminence the contrast sensitivity (ability to discern luminence values) is very small!!!! and it changes with luminence. The lower the luminence the lower the sensitivity.


Cheers

Perceived contrast can be affected by how the brain processes relative contrast. See attached optical illusion example.

The A and B squares (not the letters themselves) are the exact same color (shade of gray).
LL


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post #25 of 111 Old 05-12-2005, 11:16 AM
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Quote:


Originally posted by subysouth
Bump for some great info and a question.

Is there any way to relate the light output on a 0 IRE window to a shade of grey?

ss

If the setting is for black at 0 IRE (some systems are set to do black at 7.5 IRE), then 0 IRE = black = 0 on the greyscale spectrum.

There is no difference in HDMI cables. If you can see the picture without visible dropouts or sparklies, the cable is working at 100%. No other cable will display a better version of that picture. You're simply wrong if you think there is a better digital cable than one that is already working. (Oh, and plasma didn't die because of logistics problems, nor does OLED ship in big boxes because it comes from Korea.)
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post #26 of 111 Old 05-12-2005, 11:40 AM
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Quote:


Originally posted by rogo
If the setting is for black at 0 IRE (some systems are set to do black at 7.5 IRE), then 0 IRE = black = 0 on the greyscale spectrum.

Yea I guess what I am asking doesnt make sense maybe.

I am guessing the signal is telling the display to show no light correct? But any light is in theory gonna move the black of the darkened room to some shade of grey I would think.

Are these two seperate things?

ss
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post #27 of 111 Old 05-12-2005, 11:44 AM
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Originally posted by Rgb
Perceived contrast can be affected by how the brain processes relative contrast. See attached optical illusion example.

The A and B squares (not the letters themselves) are the exact same color (shade of gray).

I think that total contrast range contributes quite a bit to the wow factor we apply to a device, even if it cant be pulled off simultaneously on the screen.

I am still gonna err on the side of trying for the deepest and give some credence to full measured CR(not this dynamic CR fraprap) as well as ANSI CR.

That Panny ED looks strong on paper as it does in real life apparently.

If I could just get my mind around what color grey those measured 0 IRE figures are.

ss
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post #28 of 111 Old 05-12-2005, 02:53 PM
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Not that is a very big deal, but if I am reading the chart correctly:

Budget projectors
BenQ PB6200 DLP 14.48 0.021 690 283 2000 SEP 2004
Epson PL Home 10+ 11.6 0.015 773 249 1200 SEP 2004
Optoma H30 DLP 9.426 0.011 857 240 2000 SEP 2004
Mitsubishi HC900 DLP 8.401 0.005 1680 417 2000 MAR 2005


It is saying that the published manufactures CR for the Epson Home 10+ is 1200..............this is incorrect. It has 1200 lumens and 800:1 CR.

Am I reading it wrong, if so, I apologize
I also have a very hard time believing that the Optima and BenQ DLP's have lower CR's than the Epson I own..........

Sorry if I am misinterpreting.......
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post #29 of 111 Old 05-12-2005, 10:33 PM
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Originally posted by subysouth

I am guessing the signal is telling the display to show no light correct? But any light is in theory gonna move the black of the darkened room to some shade of grey I would think.

Are these two seperate things?

Yes, they are. The 0 IRE signal is still "black". But as you know, on exactly zero flat panel displays is black actually, well, black. But that illuminated state is still the "black state" at 0 IRE.

Mark

There is no difference in HDMI cables. If you can see the picture without visible dropouts or sparklies, the cable is working at 100%. No other cable will display a better version of that picture. You're simply wrong if you think there is a better digital cable than one that is already working. (Oh, and plasma didn't die because of logistics problems, nor does OLED ship in big boxes because it comes from Korea.)
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post #30 of 111 Old 05-12-2005, 10:57 PM
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Originally posted by rogo
Yes, they are. The 0 IRE signal is still "black". But as you know, on exactly zero flat panel displays is black actually, well, black. But that illuminated state is still the "black state" at 0 IRE.

Mark

Can you think of a way they could translate the light output at 0 IRE to actual IRE. Something like, 0 IRE on the Panny 42 = 8.5 IRE actual.

ss
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