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Discussion Starter · #1 ·
THIS THREAD RELATES TO THE EUROPEAN MODEL OF THE PDP-LX5090


Hi guys,


I was pointed at a recent thread entitled "P 6020: "auto brightness" ? ?" in this forum and it outlines a problem very similar to one I am having with three Kuro 5090 panels at my place of work. In the case of the other thread it came down to settings on a PS3, but in this case, it is definitely the panel and not an external device. Also, the change in black level happens immediately, there is no delay as in the other thread. I have posted previously on another forum with no joy as yet, here is what I put:
I haven't been able to find any info on this, might have to go to the Pioneer, but basically I have a query on the ability of the PDP-LX5090 (hardware revision 0350, software revision 0103) to be correctly calibrated. We have 3 of these panels of identical model and identical software and hardware revision and they do not all act alike.


Those that own this panel may or may not have noticed this, but there is a dynamic black level adjustment that occurs on the panel that basically changes what the panel displays as black according to picture content (if you output a PC desktop or similar to one of the HDMI inputs and drag a white window on and off the screen it's immediately obvious to see). No tweaking of any controls in the panel, or offered by the ISF calibration software gives you the ability to disable this behaviour. However, if you load the movie preset, two out of the three panels no longer do this black level adjustment (but one still does?!?).


I eventually found out that in movie mode if you then enable power saving (which is off by default in this mode), the automatic black level adjustment returns. You would think then that disabling power saving in the other modes would be the answer however the black level adjustment remains... On the one panel that movie mode did not disable this 'feature', nothing seems to be disable it. It seems likely that the movie preset alters a setting that otherwise cannot be accessed.


I have attempted a software upgrade through the panel itself but no new software was found, and attempted a firmware update via the usb port but this simply isn't recognised (firmware listed for PDP-LX5090H and the LX5090 doesn't see it).


The reason this is significant and I can't just calibrate under the movie mode, is because using the ISF software gives you a greater range of calibration options, but it has to be applied to its own preset which appears as ISF Day or ISF Night after the software has been used. The black level adjustments are also applied to this preset - and with the black level all over the place and hence dynamic range constantly changing, calibration is impossible...


There either are differences between the hardware/software of these apparently identical sets, or there are settings that pioneer have restricted access to, even with ISF calibration software. Or maybe some of the menu items are just not doing what they are meant to? Has anyone else had any experience of this or knows how to disable this 'feature' for a preset other than movie?

Although I have been looking at this quite extensively now, I have not been able to get to the bottom of it at all as yet. Shawn from ControlCAL has been most helpful and has been able to contact Pioneer directly about this, but even this has shown little fruit as yet - always hard to get to the heart of the matter in large organisations. I think we will be attempting to go to Pioneer directly soon if this cannot be resolved.


I have attached a spreadsheet showing the full rundown of settings in the three panels and whether or not the dynamic black level adjustment is disabled in each case. In only 2 out of 12 tested setups was the dynamic black level adjustment disabled...


Any thoughts or ideas are more than welcome.


Cheers


Jon

 

LX5090_settings.zip 9.8046875k . file
 

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Discussion Starter · #3 ·
Thanks Patrick, but thats where I posted previously



Really like to get to the bottom of this, but it's very hard to find anything on it, there must be more than the panels I have tested here that show this behaviour



Thus I shall continue to search.
 

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Quote:
Originally Posted by mpcengineering /forum/post/15437738


Thanks Patrick, but thats where I posted previously



Really like to get to the bottom of this, but it's very hard to find anything on it, there must be more than the panels I have tested here that show this behaviour



Thus I shall continue to search.

There is NOT a dynamic black level control on any Kuro. Your issue does not exist on the NA models. You need to contact Pioneer in your country or visit www.avforums.com and seek help there.
 

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I can't seem to find your post about this over at AVF, so I'll reply here.


The testing that you're doing sounds more like you're seeing the automatic brightness limiter in effect rather than any kind of black level adjustment.


There can also be slight after-images left on the screen when anything passes over a pure black background with these sets, which you may also be seeing.
 

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Discussion Starter · #7 ·
Hi Andrew,


Thanks for the reply, my post at AVF can be found here


It's a fair way down the list now as I haven't had any replies, also my username as it is here, was now allowed there so I had to change it to just engineering.


If it is more relevant I am happy to continue the discussion there as D-Nice seems confident this is not an issue apparent on any panels relevant to this forum. Anyhow, I shall reply here and then the discussion can be moved if needs be.


Automatic brightness limiter, ok well that kind of makes sense as brightness defines what the black level is, but whatever it is to be defined as - it most certainly is altering the black level, and to a significant extent. Also the affect is over the entire screen, not just the area over which the white window was been placed and so it isn't a trail left by the moving white box. Is this a known 'feature' of these panels and are you aware of any way to disable this behavior?


Also, for anyone that reads it, I haven't as yet got hold of ControlCAL as per my AVF post, partly for trying to resolve this issue first, so I do not yet know if this software can alter a setting I have not yet been able to access.
 

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I think it's fine for you to post here (since AVS is not restricted just to NA) though I do believe 2 of these panels may be defective as I emailed to you (based on the responses I got back from others over that last few weeks).


I did email this to four people including one of my contacts in Pioneer and D-Nice.


Though they/we are not at the displays to see how these tests are being done, the consensus is that this is not normal behavior on those two displays and that as D-Nice has posted, there is no option for Dynamic Black Level Control...


One thing I forget to ask, have you/can you try other sources....?


Also, can you edit Post #1 (first line in BOLD) with the statement/disclaimer that this is for the European PDP-LX5090 Models please...
 

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Quote:
Originally Posted by mpcengineering /forum/post/15439578


Hi Andrew,


Thanks for the reply, my post at AVF can be found here


It's a fair way down the list now as I haven't had any replies, also my username as it is here, was now allowed there so I had to change it to just engineering.


If it is more relevant I am happy to continue the discussion there as D-Nice seems confident this is not an issue apparent on any panels relevant to this forum. Anyhow, I shall reply here and then the discussion can be moved if needs be.


Automatic brightness limiter, ok well that kind of makes sense as brightness defines what the black level is, but whatever it is to be defined as - it most certainly is altering the black level, and to a significant extent. Also the affect is over the entire screen, not just the area over which the white window was been placed and so it isn't a trail left by the moving white box. Is this a known 'feature' of these panels and are you aware of any way to disable this behavior?


Also, for anyone that reads it, I haven't as yet got hold of ControlCAL as per my AVF post, partly for trying to resolve this issue first, so I do not yet know if this software can alter a setting I have not yet been able to access.

Let me clarify exactly why I recommended you post your concerns over @ www.avforums.com or contact your local Pioneer....


The LX5090 isn't remotely close to anything offered in NA. It doesn't even have the same hardware as even the non-Elites over here. Noone on this forum, who are primarily from the US or Canada, has your panel. This is the same reason why noone from the US or Canada should be posting on avforums.com about an issue they have with their panel.


At any rate, you are seeing this with PC based content. You need to check the type of signal you are sending the panel...is it Studio RGB or PC RGB. If it is PC, then you need to be using the PC video mode and send a PC RGB signal to the panel.
 

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Discussion Starter · #10 ·
Thanks for the post turbe and ty for the clarification D-Nice, understood and makes perfect sense. I'm just clutching at straws wherever I can trying to work this thing out!


As this is considered by those in the know to be alien behavior and thus potentially faulty equipment it looks like it is time to converse with a UK pioneer contact as to whether there is in fact a fault here or not - I will also try to confirm exactly what the behavior *should* be in the models for the UK.


Also I have noted this behavior across multiple inputs if I remember correctly, not just with a PC source (thats just the easiest to test), however I will confirm this by measuring black and white levels with our calibration equipment next week to make doubly sure. Thinking about it, should not make too much difference anyway as the input is DVI to one of the HDMI inputs, and these can equally accept a regular video source?!?
 

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From Home Theater Magazine Pioneer Elite KURO PRO-111FD Plasma HDTV 11/2008

"I did note a black-level oddity that I first saw on the PDP-6020. When I switched quickly from a bright white test pattern to video black, the black level would initially be elevated. After a few seconds, it would drop to the more typical, low level shown above. After another 15 to 30 seconds, it would drop further, to total black—as if the set had shut off (it hadn’t). But I only experienced this on test patterns."
http://hometheatermag.com/plasmadisp...tv/index4.html


From Home Theater Magazine Pioneer KURO PDP-6020FD Plasma HDTV 9/2008:

"On some occasions, when I switched from a bright white test pattern to video black, the black level appeared slightly elevated (measured at 0.008 ft-L). After a few seconds, it dropped to the 0.000-ft-L level. After another 15 seconds or so, it would drop further, to total black (judged by eye). Most of the time, the first drop was to the 0.000-ft-L “measured” level. In the 30 to 40 hours I spent watching real program material, however, I only recall seeing that 0.008-ft-L level once or twice."
http://hometheatermag.com/plasmadisp...ro/index3.html


This is why measuring (or setting) can be tricky as the time constants in the display's design making it difficult. It's a shame the pure mode cannot defeat this black level manipulation.


The actual real-world contrast ratio with standard full field (not a small white square) is calculated to be 17/0.008 = 2125


Objective, unbiased truth can be lonely here. No need to thank me!
 

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I'm not sure what you want to be thanked for..
that behavior has been known from day one..


What mpcengneering was trying to figure out if there is a Control to disable/enable this, which there is not on the Kuros. He says he has two out of three Displays that this does not happen when those two Displays are set to Movie with no Power Save. He also claims that: "the change in black level happens immediately"
 

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Well, I think what HiFiFun has at least given the OP is what professional reviewers have seen. That is more than the "I don't see it so it doesn't exist" kind of response.

What mpcengineering does with this is entirely up to him. If mpcengineering does contact Pioneer, he'll also be able to use the professional reviews to support his arguments.
 

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Quote:
Originally Posted by discopaul /forum/post/15444633


Well, I think what HiFiFun has at least given the OP is what professional reviewers have seen.

And that's especially useful information in the event I get hit in the head with a blunt object and spend the rest of my life watching test patterns while drooling on my hospital johnny.


Next.
 

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Another great testament as to why Pioneer has succeeded Sony in product worship. Recently Sony has lost its name brand marketing advantage to Samsung's performance. The transition is clear as Sony lays off employees.


Since the Pioneer design team now works for Panasonic, 2009 will be another year of transition in consumer perception. Expect Panasonic to combine the best of new technology and cast the questionable ones aside.

We shall see starting next week. Hopefully the NeoPDP panels will not resort to dynamically alter the black levels to achieve great reviews.
 

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Discussion Starter · #16 ·
Tbh, I am still very confused on this whole issue, there seems to be a huge amount of conflicting evidence. I am still unsure as to whether or not this is desired behavior or not. You say there is no behavior of this type in the NA panels, but there is also talk of an 'automatic brightness limiter' in this very thread. With however this behavior is to be described put aside, can anyone give me a definitive answer on whether I should, or should not in any circumstances be seeing any black level change on the panel? Has anyone actually gone ahead and done the test as I have described I did mine (changing between a number of different APL Pluge test signals would also amply demonstrate this)? If they have what was the outcome? I want to be able to know what to approach Pioneer with and I just find it very hard to believe 3 panels bought at different times and most likely different manufacturing batches all show a black level adjustment that just shouldn't be there? We also have just had a 4th panel come in recently, so I will be testing this next week also taking everything here into account to ensure I haven't overlooked anything - which if I have, would be welcome tbh.


I read thru your post HiFiFun, but unfortunately the behavior described there is not the same, the change in black level for the panels I have tested is both immediate and sustained, the black level does not fade back to what it should be after any time, it elevates and remains elevated as soon as 'brighter' content comes onto the screen. The truth is exactly what I am trying to ascertain....
 

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Quote:
Originally Posted by mpcengineering /forum/post/15446623


Tbh, I am still very confused on this whole issue, there seems to be a huge amount of conflicting evidence. I am still unsure as to whether or not this is desired behavior or not. You say there is no behavior of this type in the NA panels, but there is also talk of an 'automatic brightness limiter' in this very thread. With however this behavior is to be described put aside, can anyone give me a definitive answer on whether I should, or should not in any circumstances be seeing any black level change on the panel? Has anyone actually gone ahead and done the test as I have described I did mine (changing between a number of different APL Pluge test signals would also amply demonstrate this)? If they have what was the outcome? I want to be able to know what to approach Pioneer with and I just find it very hard to believe 3 panels bought at different times and most likely different manufacturing batches all show a black level adjustment that just shouldn't be there? We also have just had a 4th panel come in recently, so I will be testing this next week also taking everything here into account to ensure I haven't overlooked anything - which if I have, would be welcome tbh.


I read thru your post HiFiFun, but unfortunately the behavior described there is not the same, the change in black level for the panels I have tested is both immediate and sustained, the black level does not fade back to what it should be after any time, it elevates and remains elevated as soon as 'brighter' content comes onto the screen. The truth is exactly what I am trying to ascertain....

While I can't tell you what is going on I can tell you what is supposed to be happening. The automatic brightness limiter adjusts the brightness of picture according to the post gamma APL of the signal. It should not affect the black level.


HiFiFun likes to post that review as evidence of shifting black level but what it is describing is the startup sequence of the pioneer panels that primes the pixels. During display of a signal the black level should be completely stable. See this post describing the startup sequence (see this POST )


The reset pulse during operation is the source of luminence when displaying black. Pioneer only uses a single reset pulse (CLEAR driving) during display of any signal and therefore should have a completely stable black level.


Panasonic has in the past used a reset pulse for very subfield, and in order to get more gradation at different APL they opted to adjust the number of subfields depending on APL which in turn adjusted the number of reset pulses which in turn adjusted the black level at different APL.
 

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mpcengineering,


Exactly what type of signal are you sending these panels? Please detail it from the black setup to the color type.


Also, please provide every single piece of hardware that exist between your panel and your source equipment detailing each one. If your source equipment is a PC, please detail the specs of that PC from the CPU to the video card and video drivers used.
 

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Quote:
Originally Posted by mpcengineering /forum/post/15446623


I read thru your post HiFiFun, but unfortunately the behavior described there is not the same, the change in black level for the panels I have tested is both immediate and sustained, the black level does not fade back to what it should be after any time, it elevates and remains elevated as soon as 'brighter' content comes onto the screen. The truth is exactly what I am trying to ascertain....

I can only state what is valid for the US models.

In the future I'd suggest buying one engineering evaluation model first before committing.

In the meantime let's see what is new and improved at the CES.
 

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Discussion Starter · #20 ·
Hi D-Nice,


We have 2 sources feeding each panel, 1 is a mac mini, exactly the spec of all the hardware within, I couldn't say except for the core 2 duo processor, but it is the current model. This feeds directly from the DVI OP to the HDMI IP on the screen. I do not think that it has any bearing personally as other machines we have connected in the same way show identical behavior on the panel.


The 2nd IP comes from our facility SD/HD-SDI distribution and the only thing between the SD/HD-SDI feed and the panel is a blackmagic SDI to HDMI converter which can be found here


I can guarantee the integrity of the facility SD/HD-SDI feed, and we use the blackmagic boxes in a number of other places, so if this was making a black level adjustment I think we would have noticed by now. As for the mac mini, as far as I am aware, no issues of this nature exist with that unit. The attachment on my the initial starting post has a complete run down of all setting in all the panels this has been tested on.

Quote:
Originally Posted by HiFiFun /forum/post/15451350


In the future I'd suggest buying one engineering evaluation model first before committing.

I totally agree but unfortunately, I have no influence over what we buy and when we buy it, other people control the purse strings.

Quote:
Originally Posted by xrox /forum/post/15447822


While I can't tell you what is going on I can tell you what is supposed to be happening. The automatic brightness limiter adjusts the brightness of picture according to the post gamma APL of the signal. It should not affect the black level.

I understand what you mean, but adjusting brightness is how you set black level, do you mean peak white i.e. nit output?

Quote:
Originally Posted by mpcengineering /forum/post/15446623


With however this behavior is to be described put aside, can anyone give me a definitive answer on whether I should, or should not in any circumstances be seeing any black level change on the panel?

So according to xrox there should be no change at all in black level whatever the signal fed to the panel, can anyone else confirm?
 
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