Contradictory calibration results - THX and AVS HD 709 - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 15 Old 09-02-2009, 09:03 PM - Thread Starter
Member
 
kidicarus7's Avatar
 
Join Date: Dec 2007
Posts: 40
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
By 'calibrated' I mean brightness and contrast. That's all I'm interested in getting right at the moment. But I just don't get it. I've calibrated my Viera TH-L37G10A using the THX video calibration found on The Bourne Conspiracy PS3 demo game so that the drop shadow can't be seen on the THX logo (ie, it blends in with the background - this is supposedly 'correct') but then when I fire up AVS HD 709 (AVCHD) I have 'incorrect' brightness results.

The test I'm referring to in AVS HD is the second test under the "Misc. Patterns" main menu option. This test has two horizontal bars of vertically aligned brightness bars, one increasing in brightness, the other decreasing with one on top of the other.

At the same settings on my HDTV that are 'correct' in the THX, the results in this AVS HD test are incorrect. Black 16 and the bar that is next to it that is supposed to be brighter are the same black level. In other words, all four initial black bars are the same black level.

Now to describe my setup. My PS3 is set to limited RGB output. Superwhite is ON. DVD/BD is set to output at Y Cb Cr and I am connected to my HDTV with HDMI.

From my research I've gathered that the PS3 main menu (XMB) and games use RGB and that DVD/BD can output in either RGB or Y Cb Cr, depending on what setting is selected in the Video options of the PS3. As I've stated, in my case this is set to Y Cb Cr. So going by this information, the game and AVS HD 709 disc should both using the same base black of black 16.

So does anyone know why my results are contradictory and which test I should be using as the 'correct' one?

I will respond to PM's eventually, I swear.
kidicarus7 is offline  
Sponsored Links
Advertisement
 
post #2 of 15 Old 09-03-2009, 09:52 AM
Advanced Member
 
Gregg Loewen's Avatar
 
Join Date: Feb 2002
Location: New England
Posts: 772
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 39
probably the 2 discs have different APLs

President, Lion Audio Video Consultants Inc.
Lead THX Video Standards Instructor
Gregg Loewen is offline  
post #3 of 15 Old 09-03-2009, 10:33 AM
AVS Addicted Member
 
D-Nice's Avatar
 
Join Date: Dec 2004
Location: Columbia, SC
Posts: 14,949
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 30 Post(s)
Liked: 218
If you are attempting to setup the black level (with the brightness control on your display), you should be using the pluge pattern located in the "Basic Settings" menu of the 709 disc (its actually the first pattern in that chapter).
Quote:
Originally Posted by kidicarus7 View Post

By 'calibrated' I mean brightness and contrast. That's all I'm interested in getting right at the moment. But I just don't get it. I've calibrated my Viera TH-L37G10A using the THX video calibration found on The Bourne Conspiracy PS3 demo game so that the drop shadow can't be seen on the THX logo (ie, it blends in with the background - this is supposedly 'correct') but then when I fire up AVS HD 709 (AVCHD) I have 'incorrect' brightness results.

The test I'm referring to in AVS HD is the second test under the "Misc. Patterns" main menu option. This test has two horizontal bars of vertically aligned brightness bars, one increasing in brightness, the other decreasing with one on top of the other.

At the same settings on my HDTV that are 'correct' in the THX, the results in this AVS HD test are incorrect. Black 16 and the bar that is next to it that is supposed to be brighter are the same black level. In other words, all four initial black bars are the same black level.

Now to describe my setup. My PS3 is set to limited RGB output. Superwhite is ON. DVD/BD is set to output at Y Cb Cr and I am connected to my HDTV with HDMI.

From my research I've gathered that the PS3 main menu (XMB) and games use RGB and that DVD/BD can output in either RGB or Y Cb Cr, depending on what setting is selected in the Video options of the PS3. As I've stated, in my case this is set to Y Cb Cr. So going by this information, the game and AVS HD 709 disc should both using the same base black of black 16.

So does anyone know why my results are contradictory and which test I should be using as the 'correct' one?



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

D-Nice is offline  
post #4 of 15 Old 09-03-2009, 10:43 AM
AVS Special Member
 
Chronoptimist's Avatar
 
Join Date: Sep 2009
Posts: 2,583
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 227
Use the AVS disc, calibration in games is usually wrong because the consoles don't output BTB/WTW over RGB. Output RGB limited with the AVS disc to keep it a match to games.
Chronoptimist is offline  
post #5 of 15 Old 09-03-2009, 11:20 AM
AVS Special Member
 
alluringreality's Avatar
 
Join Date: Jul 2006
Posts: 3,166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked: 35
If you can't tell 5% apart from black, then most likely brightness is too low. An LCD could be affected by average picture level, but from what I've seen from digital displays I wouldn't necessarily expect 5% to blend with black regardless of APL. If the PS3 works as documented, then you can simply use a video pattern to set display controls and it should also work for games.

One way to set brightness in a game without a pattern is to turn up brightness too high so that the black level is raised. To start you want the darkest items in the game too bright so that they are clearly lighter. Then begin turning down brightness and watch for a loss of detail. If objects or gradations completely disappear then you have gone too low. You basically want to turn down brightness until the darkest items become no darker if you were to go low lower with brightness. There is no below-black information expected in games, so all detail in the game should display. If you turn brightness too low so that objects completely blend into black then brightness is probably too low. I've done this sort of procedure on my Xbox, and then I've compared the brightness setting against what I got from using a video pattern. Either procedure resulted in almost identical settings, so the Xbox seems to output black for video and games at the same level as expected, and for that system I'd say to just use a video pattern to set brightness as commented above.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
alluringreality is online now  
post #6 of 15 Old 11-26-2012, 05:46 AM
Senior Member
 
Tyrone Burton's Avatar
 
Join Date: Oct 2012
Location: UK,Cheshire
Posts: 466
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Hiya guys.

Are you saying that if video games on consoles don't output BTB/WTW, you should calibrate the so the next one up to below black is barely visible? If you understand that.

I'm guessing PCs output BTB/WTW.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Tyrone Burton is offline  
post #7 of 15 Old 11-26-2012, 02:36 PM
AVS Special Member
 
Doug Blackburn's Avatar
 
Join Date: May 2008
Location: San Francisco - East Bay area
Posts: 3,453
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 21 Post(s)
Liked: 226
You may be getting 2 completely different things when you use a Game and a test/setup disc designed to get you to the right settings for movies. Games tent to be RGB 0-255 while movies are encoded in YCbCr 4:2:0 (and are usually best output from the disc player as YCbCr 4:2:2). If you setup with the game disc, then switch to a movie, you're likely to have blacks and shadows that are much too bright (black never gets black, just dark gray).

If you calibrate with the test/setup disc first, then play a game, you're likely to lose most of the shadow detail. The best solution for this is for your TV to have separate memories for each input so you can set the input used for gaming to RGB 0-255 so your setting for black will be correct for games. And so you can save a completely different Brightness setting for your movie input from the disc player.

Anothe fix is to set the game console to output RGB 16-235 or YCbCr 4:2:2 so that your games and movies will share the same black level. Some people have a serious aversion to doing that because they think they will lose something visible from the games, but it's doubtful the difference would be visible.

You could also set the disc player to output YCbCr at 0-255 (if the player has that option) or RGB 0-255 (again, if the player has that option) so that both movies and games would have the same black level.

"Movies is magic..." Van Dyke Parks
THX Certified Professional Video Calibration
ISF -- HAA --
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Widescreen Review -- Home Theater & Sound
Doug Blackburn is offline  
post #8 of 15 Old 11-26-2012, 04:27 PM
Senior Member
 
Tyrone Burton's Avatar
 
Join Date: Oct 2012
Location: UK,Cheshire
Posts: 466
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
I thought Video games used the REC 709/sRGB space. Well the artists anyway. Which is what movies use, including the calibration discs. Or is it the YCBCR 4:2:0 in the way of doing it that way?


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Tyrone Burton is offline  
post #9 of 15 Old 11-26-2012, 05:33 PM
AVS Special Member
 
sotti's Avatar
 
Join Date: Aug 2004
Location: Seattle, WA
Posts: 6,621
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked: 167
Quote:
Originally Posted by Tyrone Burton View Post

I thought Video games used the REC 709/sRGB space. Well the artists anyway. Which is what movies use, including the calibration discs. Or is it the YCBCR 4:2:0 in the way of doing it that way?

YCC 4:2:0 is a way of encoding RGB data. It's effectively a compression scheme and is how DVD and Blu-ray store their content. HDMI uses YCC 4:2:2 or 4:4:4 for transmission.

YCC, like RGB is a relative colorspace. You have no idea how Red 255,0,0 is until you say that it's for sRGB, then you know it's x,y 0.64,0.33. The same goes for YCC, it's just a different way to pack the relative colormetric data that makes it take up less space for transmission.

If you want a good primer on the conversion read this http://www.dvd-replica.com/DVD/color.php


I think Doug missed in the original post that the console is setup correctly for optimum output, so this difference is either an issue with a dynamic contrast setting or is being caused by a bad encode on the THX optimizer. The THX optimizers are notorious for having the wrong levels.

Joel Barsotti
SpectraCal
CalMAN Lead Developer
sotti is online now  
post #10 of 15 Old 11-27-2012, 04:18 AM
Senior Member
 
Tyrone Burton's Avatar
 
Join Date: Oct 2012
Location: UK,Cheshire
Posts: 466
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Yep. The only THX Optimiser I have found that matches results you'd find on a proper calibration disc is on the Star Wars DVDs. The Terminator 2 BD had a bad Optimser, came up on my TV very dark.

Some people say that the reason some if them are wrong is because their either movie specific or game specific. Seems like it's just badly made optimisers then.

Oh THX. Your confusing people ya know smile.gif


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Tyrone Burton is offline  
post #11 of 15 Old 04-28-2014, 05:52 AM
Member
 
BigSteve82's Avatar
 
Join Date: Dec 2008
Posts: 192
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I noticed something similar recently with my setup, but not using a PS3...

So, I've had a Samsung HL61A750 since about 2008 and it's still going strong. I calibrated it many years ago (using AVSHD.709) and haven't touched the settings since because it looked so good. Recently, however, I began watching the Life series on Bluray and noticed that it had a calibration tool on the disc, so I decided to test it out. Everything seemed perfect except for the brightness setting.

Using the AVSHD.709 disc years ago, I set the brightness to 47 which allowed the bars numbered 17 and up to flash. Turning it down to 46 clipped number 17; setting it to 45 clipped 18; and so on.

On the Life Bluray, the calibration tool uses a screen with A, B, and C bars and tells you to adjust the bars until the A and B bars completely disappear and the C is barely visible. As my TV was set, the A and C were completely visible (B was invisible no matter what) and the background was grey rather than black. Adjusting the brightness of my set to comply with this test resulted in the brightness being dropped to 35. At 35, the A bar disappeared and C was barely visible.

No other settings had changed.

I put the AVSHD.709 disc back in and noticed that on the brightness calibration tool, NO bars were flashing. Every bar was solid black.

Wondering why there was such a difference, and thinking that it was perhaps a problem with the calibration tool on the Life Bluray, I decided to hunt through my collection to find other discs with calibration tools. I located two different THX calibration tools and one Disney calibration tool.

Using these three different calibration tools, the brightness setting matched that of the Life Bluray and completely contradicted the AVSHD.709 disc. Changing the brightness setting on my set from 47 to 35 (and back and forth) while watching an actual movie resulted in some pretty impressive differences and actually looked much better at 35 and I notice no crushing of blacks anywhere in the scene(s).

Does anyone know why there is such a difference? This was all done from a Samsung F5900 3D Bluray player, using HDMI, but the Bluray player has no setting for changing HDMI Black Level so I assume it's set by default to limited/normal. I cannot change the HDMI black level on my set as it's greyed out while using Bluray.

Also, thinking that it was perhaps a problem with my Bluray player, I tried all four of the above mentioned discs with the PS4 and yielded the exact same results.

Something else that I noticed is, using the brightness setting of 35 and playing PS4 (RGB/Color set to Full) and 360 (set to Expanded and RGB), games DO appear to have crushed blacks. Changing them to limited HDMI output seems to correct the issue.

Have I had the wrong setting for this television for all these years?!
BigSteve82 is offline  
post #12 of 15 Old 04-28-2014, 06:01 AM
AVS Special Member
 
ConnecTEDDD's Avatar
 
Join Date: Sep 2010
Location: Athens, Greece
Posts: 2,312
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 96 Post(s)
Liked: 472
Quote:
Originally Posted by BigSteve82 View Post

I noticed something similar recently with my setup, but not using a PS3...

So, I've had a Samsung HL61A750 since about 2008 and it's still going strong. I calibrated it many years ago (using AVSHD.709) and haven't touched the settings since because it looked so good. Recently, however, I began watching the Life series on Bluray and noticed that it had a calibration tool on the disc, so I decided to test it out. Everything seemed perfect except for the brightness setting.

Using the AVSHD.709 disc years ago, I set the brightness to 47 which allowed the bars numbered 17 and up to flash. Turning it down to 46 clipped number 17; setting it to 45 clipped 18; and so on.

On the Life Bluray, the calibration tool uses a screen with A, B, and C bars and tells you to adjust the bars until the A and B bars completely disappear and the C is barely visible. As my TV was set, the A and C were completely visible (B was invisible no matter what) and the background was grey rather than black. Adjusting the brightness of my set to comply with this test resulted in the brightness being dropped to 35. At 35, the A bar disappeared and C was barely visible.

No other settings had changed.

I put the AVSHD.709 disc back in and noticed that on the brightness calibration tool, NO bars were flashing. Every bar was solid black.

Wondering why there was such a difference, and thinking that it was perhaps a problem with the calibration tool on the Life Bluray, I decided to hunt through my collection to find other discs with calibration tools. I located two different THX calibration tools and one Disney calibration tool.

Using these three different calibration tools, the brightness setting matched that of the Life Bluray and completely contradicted the AVSHD.709 disc. Changing the brightness setting on my set from 47 to 35 (and back and forth) while watching an actual movie resulted in some pretty impressive differences and actually looked much better at 35 and I notice no crushing of blacks anywhere in the scene(s).

Does anyone know why there is such a difference? This was all done from a Samsung F5900 3D Bluray player, using HDMI, but the Bluray player has no setting for changing HDMI Black Level so I assume it's set by default to limited/normal. I cannot change the HDMI black level on my set as it's greyed out while using Bluray.

Also, thinking that it was perhaps a problem with my Bluray player, I tried all four of the above mentioned discs with the PS4 and yielded the exact same results.

Something else that I noticed is, using the brightness setting of 35 and playing PS4 (RGB/Color set to Full) and 360 (set to Expanded and RGB), games DO appear to have crushed blacks. Changing them to limited HDMI output seems to correct the issue.

Have I had the wrong setting for this television for all these years?!

Hi, If you used the Brightness Pattern of Terminator Skynet Edition Region B Blu-Ray....has incorrect levels.

If you try to set your brightness level with this pattern you will receive a picture without shadow detail & all information above black will disappear, huge black clipping.

Avoid Completely that Terminator Skynet Edition Disk for Setting Brightness and propably any other disk that include that THX Optimizer chapters... T2's is an upscalled DVD Pattern version that they added them to Blu-Ray Disk my mistake.

THX Calibrator Blu-Ray Disc is accurate.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

S/W: LightSpace CMS, SpaceMan ICC, SpaceMatch DCM, CalMAN 5, CalMAN RGB, ChromaPure, CalPC, ControlCAL
Meters: JETI Specbos 1211, Klein K-10A, i1PRO2, i1PRO, SpectraCAL C6, i1D3, C5
ConnecTEDDD is online now  
post #13 of 15 Old 04-28-2014, 06:29 AM
Member
 
BigSteve82's Avatar
 
Join Date: Dec 2008
Posts: 192
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by ConnecTEDDD View Post

Hi, If you used the Brightness Pattern of Terminator Skynet Edition Region B Blu-Ray....has incorrect levels.

If you try to set your brightness level with this pattern you will receive a picture without shadow detail & all information above black will disappear, huge black clipping.

Avoid Completely that Terminator Skynet Edition Disk for Setting Brightness and propably any other disk that include that THX Optimizer chapters... T2's is an upscalled DVD Pattern version that they added them to Blu-Ray Disk my mistake.

THX Calibrator Blu-Ray Disc is accurate.

Thanks for the reply...
The Bluray discs I used were the following:
Terminator 2
Disney's WOW!
Indiana Jones and the Kingdom of the Crystal Skull

...all 3 of those contradicted the AVSHD.709 disc. I have Avia and DVE calibration DVDs that I'll try whenever I get home this evening, but not sure how its SD standards will work with HD.

EDIT: Also, where can I get that THX Calibrator Disc you linked to? Surprisingly, there are not very many HD calibration discs available on Bluray other than DVE (which I've heard bad things about on Bluray).
BigSteve82 is offline  
post #14 of 15 Old 04-28-2014, 08:15 AM
AVS Special Member
 
Chad B's Avatar
 
Join Date: Oct 2002
Location: Piqua, OH
Posts: 2,069
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 57 Post(s)
Liked: 349
Nothing wrong with the DVE bluray other than common limitations with window sizes, saturations, etc.

touring calibrator
Jeti 1211

Latest reviews:


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Chad B is online now  
post #15 of 15 Old 04-28-2014, 09:29 AM
AVS Special Member
 
alluringreality's Avatar
 
Join Date: Jul 2006
Posts: 3,166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked: 35
Quote:
Originally Posted by BigSteve82 View Post

I have Avia and DVE calibration DVDs that I'll try whenever I get home this evening, but not sure how its SD standards will work with HD.

The gray decode is exactly the same, so usually the brightness setting on DVD and Blu-ray is expected to match exactly. The only time I personally haven't seen matching black levels from a video decode was on a computer, which was corrected by replacing the video drivers. Generally the DVD versions of Avia and DVE should work for setting brightness to watch Blu-ray.

The pluge patterns used for Avia and DVE are within the range shown on Basic Settings chapters 1 & 2, so I would expect that using those discs should result in some flashing bars on the AVS patterns. The first level above black is higher than luma 17 on both of these discs, which is basically why the current PDF for AVS suggests you should be able to notice something like the 19 bar flash on Basic Settings chapter 2 from your typical viewing position. That sort of suggestion should generally match up with the Avia and DVE instructions with most displays. I'm thinking the first bar above black on the first Avia might have been 18 or 19, and I think DVE uses 20 for their 2% bar. If you turn brightness down to clip at the bars shown on Avia or DVE, it's possible to cut off a few levels above black, which should be reflected on the AVS patterns. What you wrote does not seem to indicate a decoding problem, so I have to expect Avia and DVE instructions will not match with the patterns you previously listed.

Quote:
Originally Posted by BigSteve82 View Post

Changing the brightness setting on my set from 47 to 35 (and back and forth) while watching an actual movie resulted in some pretty impressive differences and actually looked much better at 35 and I notice no crushing of blacks anywhere in the scene(s).

Generally altering the brightness control simply changes which levels a digital TV will display near black. As you lower the brightness control it will make higher levels darker, but once you go past reference black it simply eliminates near-black information as you go lower. The 25 bar is around 4% of the video range, so if 25 is not flashing you're eliminating at least 4% of the video information near black. On very dark scenes it should be possible to notice that some near-black information is lost when comparing a brightness setting that displays no near-black bars on the AVS patterns against a setting that allows the 17 bar to display. Yes, it is generally preferable to lower the brightness of black and near-black information, but all you can really reasonably do is to lower the backlight (LED Control) to the minimum setting that's acceptable for white. After lowering the backlight control you're simply dealing with the display's limitations and reducing the brightness control primarily eliminates near-black information as the display continues to darken.

I believe the DVE instructions suggest that 2% (luma 20) should display, so in that context not displaying more than 4% of the range would be considered crushing near-black information. Color bars have their pluge closer to 4%, so in that context displaying luma 25 wouldn't necessarily be considered crushing near-black information. Ideally the display would have both a brightness and gamma control, so that you could change both where the TV clips and how quickly it comes out of black, but only a few newer displays tend to have gamma controls. Without having both a brightness and gamma control, you probably have to choose how much near-black information you want to cut off as you darken the display with the brightness control. A lot of calibration recommendations came out of a time when only analog displays existed, so there are some areas of digital display calibration that are not precisely defined. Personally I think cutting off 4% of the range would be too much and is clearly noticeable on dark scenes with my TV, but different displays have various minimum light levels and come out of black at different rates. Lowering the brightness control does not affect minimum light level, but lowering the brightness control does tend towards measuring more like a display with a higher gamma.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
alluringreality is online now  
Reply Display Calibration

User Tag List

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


Forum Jump: 

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

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