or Connect
AVS › AVS Forum › Display Devices › Plasma Flat Panel Displays › LG Plasma Panel tweaks for better blacks.
New Posts  All Forums:Forum Nav:

LG Plasma Panel tweaks for better blacks. - Page 41

post #1201 of 1390
Actually i didn't use a multimeter, so i couldn't measure. Just my bare eyes.
Correct, i went counter clockwise.

This morning, cold start and no green/pink pixels.
I put it half way counter clockwise.

When i first tweaked i had two problems : the noise in bright scenes and the green/pink pixels on a cold start. I got rid of the noise tweaking the VS clockwise, but not too much or i would get more green/pink pixels (just a hair or two from its original place).

I thought i should turn the other pots slowly and check the effects on my cold start up. This is when i realized that the VZB (turned almost totally clockwise) was causing all those green/pink pixels. So i turned it half way counter clockwise and bam, adios.

I kinda just gave myself enough room to turn both Set_up and Set_Dn fully clockwise (which resulted in really deep blacks). Then, to completely assure i wont have anymore noise or green pixels on start up, i turned the Set_Dn a bit counter clockwise.

I kinda tweaked each pot when needed, like a engine, to get the best image.
First i would check their effect, turning them totally clockwise and counter clockwise. And accordingly i would adjust them.

As for their initial positions, honestly i can't remember where they were, and i don't wanna remember ! It's 100x much better now.
post #1202 of 1390
Quote:
Originally Posted by brody76 View Post

Actually i didn't use a multimeter, so i couldn't measure. Just my bare eyes.
...
As for their initial positions, honestly i can't remember where they were, and i don't wanna remember ! It's 100x much better now.

So the guy who started out saying it was stupid to mess with your settings in any way is now haphazardly turning every pot in there without benefit of a meter or scope and without even the safety net of having first recorded the initial positions??? I got to laugh at least a little at that ;-)

My advise is slow down. Buy a cheap 15 dollar meeter and set all the pots back to spec and go from there adjusting set up/down by eye. The interaction of all the other voltages is complex. When one aspect of the picture becomes better, another may become worse. MLL is not the only quality worth optimizing.
post #1203 of 1390
Right, after trying out the tweak i couldn't help but to totally change my mind.

Only idiots don't change, right ?

Well i don't need any actually, i finished tweaking.
My last concern were the pixels on a cold start, they're now gone and i don't intend to tweak it anymore.

But thanks for your concern.
post #1204 of 1390
Thread Starter 
Quote:
Originally Posted by brody76 View Post

You've probably already made irreversible damages.

Deeper blacks by f*cking up your TV and shortening considerably it's lifespan, sounds cool ...

I wonder how many idiots fell into this ...

Quote:
Originally Posted by brody76 View Post

Ok ... first off i'd like to say sorry for being an ass in my previous posts.
I did the tweak last night and .... OMFG, it's another TV.........


I'd like to apologize again for my previous posts.
Hope it helped.

Cheers.

Quote:
Originally Posted by rpauls View Post

So the guy who started out saying it was stupid to mess with your settings in any way is now haphazardly turning every pot in there without benefit of a meter or scope and without even the safety net ...........

I think Brody really wanted to do the tweaks all along

.....but seriously, who in their "right" mind is going to start taking their new plasma apart and start turning knobs, he just needed a little encouragement to the "left" mind.
post #1205 of 1390
Quote:
Originally Posted by brody76 View Post

I kinda just gave myself enough room to turn both Set_up and Set_Dn fully clockwise (which resulted in really deep blacks). Then, to completely assure i wont have anymore noise or green pixels on start up, i turned the Set_Dn a bit counter clockwise.

Wow. I must say, I wished, I could go that far without missfires!

In regards to the cold start up-missfires I found out for my set, that Set_Up isn't responsible for them but Set_Dn only.

VZB is just before falling of the cliff. If I would turn it more counterclockwise, the missfires after a cold start would probably never came back, but the PQ would be really bad in the shades 5IRE to 20IRE.

Maybe I will give the new PM9700 a shot this year.
post #1206 of 1390
Too bad, on my side I saw no real difference concerning the VZB (turned clockwise more than half will just give more green pixels).

My colors still look good, and most importantly natural.

The PM9700 looks stunning.
post #1207 of 1390
Quote:
Originally Posted by rob80b View Post


D

Classic! Are we the devils or angels in this case ;-)
post #1208 of 1390
Quote:
Originally Posted by marcuse1979 View Post

Another problem that Set_up too much clockwise produces is "black bars bleeding", I mean, in a film with black bars, if a near to black image is next to the black bar, the absolute black of the bar partially "invades" the image. I noticed this in "The incredible Hulk", 1 exact hour of film I think, Norton's nape overlaps the upper black bar and this effect appears.

Can anyone confirm if this is indeed resulting from the tweak or if this is a more common problem with (LG?) plasmas? I did the tweak a few days ago (I only adjusted set_up and Vy) and noticed that this "black bars bleeding" seems to occur on my TV (LG PK350) too with some specific settings (brightness and gamma seem to be the biggest contributing factors). I really wouldn't want to go through the trouble of opening the TV again, so I'd be glad if anyone could shed some light on this (admittedly relatively small) problem.

Also, I noticed that with those same settings I could see some slightly faint, red PWM noise on the black bars. Now, I've had PWM noise before when I set the brightness high enough, but usually it's more of a greenish color. Could the tweak affect and increase the PWM, or am I simply looking too much into this and only now seeing things that have always been there?
post #1209 of 1390
I always had the screen bleeding , it's a plasma thing I guess ?
(but LG has it bad)

if people stand before window blinds, the lines seem to go through them
and subtitles also show lines on some light colored backgrounds.

I now (after the tweak) have more red noise than green noise in the black bars
but you can adjust it using the 5 IRE settings. (I did)
Plasma uses dithering to create colors (dark tints)
if the speckles aren't visible from a distance leave it
it's normal.

My TV does show red pixels first 3 minutes after startup (cold) but then everything is fine.

I guess my next tv will be a good full led backlight or Oled when affordable in 2 years. (hoping to keep my 2010 50PK550 till then)
post #1210 of 1390
Thread Starter 
Quote:
Originally Posted by Kumiorava View Post

Can anyone confirm if this is indeed resulting from the tweak or if this is a more common problem with (LG?) plasmas? I did the tweak a few days ago (I only adjusted set_up and Vy) and noticed that this "black bars bleeding" seems to occur on my TV (LG PK350) too with some specific settings (brightness and gamma seem to be the biggest contributing factors). I really wouldn't want to go through the trouble of opening the TV again, so I'd be glad if anyone could shed some light on this (admittedly relatively small) problem.

Also, I noticed that with those same settings I could see some slightly faint, red PWM noise on the black bars. Now, I've had PWM noise before when I set the brightness high enough, but usually it's more of a greenish color. Could the tweak affect and increase the PWM, or am I simply looking too much into this and only now seeing things that have always been there?

Hi Kumiorava

We’ve discussed this before but if the pots are properly adjusted to match the tolerance of each panel there should be no noise within the black bars with Blu-ray and most streaming, although some wide screen transfers and broadcast have incorporated the black bars, therefore instead of 0 information it’s part of the picture and dithering (noise) may be visible.
On my PG25 and PX950 there is no visible noise in the black bars regardless of were the contrast and brightness are set, they just get darker or lighter.
You want to try again adjusting the Set_up and Set_dn while watching dark scenes to remove obvious dithering in the bars although you may not achieve the desired MLL.

So yes the tweak affects and can increase the PWM. What is your source?
post #1211 of 1390
Quote:
Originally Posted by rob80b View Post

Hi Kumiorava

On my PG25 and PX950 there is no visible noise in the black bars regardless of were the contrast and brightness are set, they just get darker or lighter.
You want to try again adjusting the Set_up and Set_dn while watching dark scenes to remove obvious dithering in the bars although you may not achieve the desired MLL.

So yes the tweak affects and can increase the PWM. What is your source?

Interesting. I have always had some dithering in the black bars, even before the tweak. If I left the brightness level to the optimal setting (bar 17 still visible on the AVS HD 709 test pattern) I would have dithering in the black bars, but if I reduced the brightness one step it would disappear but the blacks would then also lose some of the detail. I suppose this could be avoided with a proper calibration?

This happens when I play Blurays with my PS3. With my PC I can use settings that allow the optimal brightness without any dithering.

Anyway, I think I must open the TV again, because today I noticed some misfiring pixels on very bright areas of the picture. I suppose these would go away after the TV warms up a bit, but it still bothers me somewhat. I think I'm just going to turn the set_up knob down a tad and not touch the others at all, I don't have the patience for trying a million different settings to find the optimal one. I leave that to the more skilled and patient tweakers :P Maybe this way I could reduce the red PWM a bit too, who knows.

What I'm still wondering about are the black bars "invading" the picture. Now, I'm not talking about line bleeding, I know that's a problem with all plasmas and it hasn't really bothered me. The problem I'm talking about is kind of hard to explain, but I'll try to take a picture of it when it gets darker to better illustrate it.
post #1212 of 1390
Okay, I managed to take a photo that shows the "bleeding black bars" problem:



See that red line below the black area? That's the problem I'm talking about, it almost seems as if the red dithering somehow bleeds from the black bars to the actual picture area in some of the darker scenes. I can only really reproduce it using the medium gamma setting, and it seems to get worse when I lower the brightness. Weird... I'll have to see if it goes away when I tweak the pots a bit more.

Oh, and sorry about the bad image quality, it's taken with my phone and I had to use the night mode to make the red line properly visible in the photo.
post #1213 of 1390
Thread Starter 
Quote:
Originally Posted by Kumiorava View Post

Okay, I managed to take a photo that shows the "bleeding black bars" problem:



See that red line below the black area? That's the problem I'm talking about, it almost seems as if the red dithering somehow bleeds from the black bars to the actual picture area in some of the darker scenes. I can only really reproduce it using the medium gamma setting, and it seems to get worse when I lower the brightness. Weird... I'll have to see if it goes away when I tweak the pots a bit more.

Oh, and sorry about the bad image quality, it's taken with my phone and I had to use the night mode to make the red line properly visible in the photo.

Ok, see what you mean, not too sure if it's from tweaking but lowering the MLL may have made it more obvious and as you mentioned it may have been there before. Might be a video processing problem but hard to know if it's the set or the source. Are the PC3 and PC hooked up to different ports or going through a receiver?
post #1214 of 1390
Quote:
Originally Posted by rob80b View Post

Are the PC3 and PC hooked up to different ports or going through a receiver?

They are hooked up to different HDMI ports, and now that I did the tweaks again to reduce the misfiring pixels I noticed that it had no effect on the noise in the black bars or the bleeding edges, so those have probably always been there and I just haven't noticed them Which is no wonder, because to be honest they aren't really noticeable from my normal viewing distance. I suppose I just got a bit carried away with all this stuff
post #1215 of 1390
Thread Starter 
Quote:
Originally Posted by Kumiorava View Post

They are hooked up to different HDMI ports, and now that I did the tweaks again to reduce the misfiring pixels I noticed that it had no effect on the noise in the black bars or the bleeding edges, so those have probably always been there and I just haven't noticed them Which is no wonder, because to be honest they aren't really noticeable from my normal viewing distance. I suppose I just got a bit carried away with all this stuff

Hi Kumiorava

I just tried an experiment and maxed out the "sharpness control" on the PG25 and PX950 to see if I could duplicate the problem and sure enough the picture would bleed into the black bars similar to what you have shown also I believe there was more noise in the blacks, lowering the sharpness of course brought things back to normal, maybe you had increased it at some point and forgot or LG over adjusted the sharpness at the factory.
So you may want to check your sharpness control, worth a try.
post #1216 of 1390
Thread Starter 
Quote:
Originally Posted by rob80b View Post

Hi Kumiorava

I just tried an experiment and maxed out the "sharpness control" on the PG25 and PX950 to see if I could duplicate the problem and sure enough the picture would bleed into the black bars similar to what you have shown also I believe there was more noise in the blacks, lowering the sharpness of course brought things back to normal, maybe you had increased it at some point and forgot or LG over adjusted the sharpness at the factory.
So you may want to check your sharpness control, worth a try.

Hi Kumiorava

Here's an example of line bleed happening on black bars when sharpness was increased on my 42PG25 (720dpi).

Sharpness maxed out.


Sharpness lowered to 30
post #1217 of 1390
Hi,

Thanks for the tip, I tried reducing the sharpness but it didn't help I investigated the problem a bit further, and using the color filters available at the settings menu I noticed that with certain brightness/gamma settings the green pixels don't light up in the areas near the black borders. Now, the weird thing is, when I turn the red brightness in the advanced settings down two notches the problem seems to disappear, but then it also introduces lots of pwm noise in the black bars that wasn't visible before. I've no idea what's going on here...

And sorry for the offtopic everyone, wasn't my intention to capture this thread.
post #1218 of 1390
Hey guys, getting a 50PA6500 soon.
Anyone knows if the pots are still there and tweakable on the 2012 models ?

I'm gonna check the blacks out of the box, if i'm satisfied i might not tweak it yet (heard that one of the major improvements on the 2012 models are deeper blacks).
But i'd still like to take a peek inside to see if i can get better for my money.

I'll let you guys know.
post #1219 of 1390
Thread Starter 
Quote:
Originally Posted by brody76 View Post

Hey guys, getting a 50PA6500 soon.
Anyone knows if the pots are still there and tweakable on the 2012 models ?

I'm gonna check the blacks out of the box, if i'm satisfied i might not tweak it yet (heard that one of the major improvements on the 2012 models are deeper blacks).
But i'd still like to take a peek inside to see if i can get better for my money.

I'll let you guys know.

Hi Brody

Just quote myself
Quote:
Originally Posted by rob80b View Post

While out enjoying the sunshine dropped into my local 2001 Audiovideo who happened to have the 50PM6700 on display in between last years 50PZ750 and the 50GT30. Showroom environment was basically low-lit ambient light and the sales guys at least stayed away from vivid modes and have the sets at their best un-calibrated settings.
Again I found the LGs to have decent gray scale, the GT30 would need a little tweaking, black levels under the given lighting conditions were comparable between the PM6700 and the GT30, I assume that would change in a dark room in favor of the GT30, the PZ750 was obviously lighter so at least LG have taken lowering the MLL seriously this year.....

Over all without being anal IMHO the 6700 appears to be a descent set and under showroom conditions is a competitive unit ..........

If the 6500 is comparable to the PM6700 I looked at it should be okay out of the box,......but since you've crossed over to the dark side that may be just a short while before the screw drivers come out.
post #1220 of 1390
Thanks rob.

The 2 sets are pretty close in terms of specs, just that the 50PM6700 is 3D ready.

You pretty much confirm what i was reading around the internet, the 2012 models have deeper blacks. But like you said, i might not resist the temptation.

Already trying to imagine what i could accomplish giving those pots a few turns.
post #1221 of 1390
Does anyone know about the PM4700 series and its ability?
I want something <50'' so the LG PM4700 and Panny UT50 are my only choices and the UT50 already seems out of production.
post #1222 of 1390
Quote:
Originally Posted by wingman1659 View Post

Does anyone know about the PM4700 series and its ability?
I want something <50'' so the LG PM4700 and Panny UT50 are my only choices and the UT50 already seems out of production.

The PM4700 looks identical to the other models too except it's not full HD and 3D ready.

I expect identical performance from the PM6700/PA650/PM4700/PA4500 except some details that differ from each other (3D, Full HD, etc..).

Only the high end model PM9700 seems to show significant difference in terms of performances (contrast, blacks, etc..).

The advantages of this set are 3D, Smart TV, Magic remote, Wifi.

Edit :

To answer to myself concerning better blacks on 2012 models :

Quote:
"The PA6500 series are the top tier of non-3D plasmas from LG for 2012. It has a 1080p plasma panel and a new black filter but cuts cost by eliminating features such as 3D and online connectivity.
The 50PA6500 has a new black filter that increases both black levels and contrast for a greatly improved picture over previous models. Along with the improved black levels and contrast comes improved color and improved detail in dark scenes and shadows. LG has stepped it up with their 2012 plasmas showing a marked improvement over previous models."
post #1223 of 1390
Hey, guys, rob, folks, reporting on my PA6500 and bringing in some pretty good news. You're gonna wanna listen to this.

Was sitting in front of my brand new 50PA6500 this afternoon, tweaking the settings and contrast and enjoying the set. The blacks are really good out of the box and the image is sweet.

Then I starting thinking, and I finally decided to get a screw driver and open it up to see how it looks like in there. Wasn't intending to tweak yet, just take a peek inside ...

It looks almost identical to my previous PZ250, except some slight changes.

The Set_up and Set_Dn are now called RAMP_up and RAMP_Dn on the new 2012 models. The basically have the same effect when you turn them clockwise : DEEPER BLACKS.

I turned RAMP_UP fully clockwise, and BOOM : even deeper blacks.
I was stunned, IT'S STILL WORKING.

Then I decided to play a bit with the RAMP_DN, BOOM : even deeper blacks.
At that moment my jaw just fell on the ground.

I couldn't believe my eyes, the blacks were already stunning out of the box, but now they look SEXY. This is unbelievable.

It didn't take much to eliminate the artifacts generated by the full clockwise RAMP_UP, I slightly (a hair) turned it counter clockwise and everything disappeared. Tested very bright scenes and tested break-in slides, nothing to report at the moment.

Waiting tomorrow morning to see what it looks like after a cold start.

But it's looking good so far.
post #1224 of 1390
Hehe

Very cool! Were the artifacts introduced by setting Ramp-Up building in form of missfires or pixelnoise?

If it was noise, maybe Vy- could do something useful and/or Va.
post #1225 of 1390
Hi Turrican, It was reddish/pinkish noise, like big stains that covered the screen (by the way, wasn't that one of the symptoms of some Panasonic panels too ? ).

Actually, I could achieve really impressive blacks, to the point where I couldn't possibly know if the TV was On or Off in a dark room. It was pitch dark blacks !

Unfortunately impossible to keep these blacks, my screen was covered by those pink stains (I tried a lot of combinations with Vy and Va, nothing would diminish them or make them go away).

So I went back to stock and slowly lower, and I could achieve really deep and sexy blacks. Stunning.

On my panel the RAMP_Dn is already in the sweet spot, so all I needed to do was slowly turn RAMP_UP clockwise and compensate with other pots to keep a stable and juicy image. I let it cool down for a few hours and turned it back on, no pixel misfire so far, looks amazing. I stopped just where I needed too, where the "the stains" would start to appear on my screen.
post #1226 of 1390
@Brody

is the PA6500 a lot better than your 50PZ250 ?
blacks and color ?
what about burn-in and line bleeding , any better ?

Thanks
Renzo

(tempted to replace my PK550 by a PM6700)
post #1227 of 1390
Hi rb, yes much better, no doubt about it.
Right out of the box it was evident, better colors, blacks, more bright image.

The black is still bleeding from time to time, especially when you tweak the pots for deeper blacks, unfortunately. But from my viewing distance I don't see it, so I it's not an issue to me.

The blacks of the PA6500 out of the box were identical if not better then my PZ250 tweaked blacks.
Now that I tweaked the blacks on my new PA6500 it just blows it out of the water.

You can tell that LG did a better job this year, I barely had to move the pots for deeper blacks.
It looks like they did tweak it a bit before it left the factory.

As for IR, less than my PZ250 too. But still noticeable when you pop up a menu for a few minutes, but disappears quickly.
post #1228 of 1390
I just saw "Immortals" again on my new PA6500.
It was another movie, I can't believe I missed all those details.

I missed at least 30% of the movie.

It's a pretty dark movie but the PA6500 deals perfectly with it, the details in dark scenes are impressive. Even more with the tweaked blacks.

The PZ250 lacked of details in dark scenes, the blacks were too "grey", so your eyes were struggling, especially in such a dark movie.

But on the PA6500 it was just amazing, stunned, really.
post #1229 of 1390
Quote:
Originally Posted by Kumiorava View Post

Okay, I managed to take a photo that shows the "bleeding black bars" problem:



See that red line below the black area? That's the problem I'm talking about, it almost seems as if the red dithering somehow bleeds from the black bars to the actual picture area in some of the darker scenes. I can only really reproduce it using the medium gamma setting, and it seems to get worse when I lower the brightness. Weird... I'll have to see if it goes away when I tweak the pots a bit more.

Oh, and sorry about the bad image quality, it's taken with my phone and I had to use the night mode to make the red line properly visible in the photo.

The image does not invade the black bars. In fact it is the opposite and yes, this is a known bug of LG plasmas!

It results in faulty rendering of the shades near black. They are not able to reach the left, the right and the top of the panel and if you would try to display a circly with an IRE of 4 for example, the circle would be rendered as an egg instead!

I really hope, LG got rid of this problem in 2012.
post #1230 of 1390
Quote:
Originally Posted by brody76 View Post

I just saw "Immortals" again on my new PA6500.
It was another movie, I can't believe I missed all those details.

I missed at least 30% of the movie.

It's a pretty dark movie but the PA6500 deals perfectly with it, the details in dark scenes are impressive. Even more with the tweaked blacks.

The PZ250 lacked of details in dark scenes, the blacks were too "grey", so your eyes were struggling, especially in such a dark movie.

But on the PA6500 it was just amazing, stunned, really.

Awesome, Im glad you opened her up cand got good results cause im getting a 60PM6700 shipped this week and was wondering if this tweak would work with my model, it looks like it possibly can... So stoked! Especially since im getting it at cost!
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Plasma Flat Panel Displays
AVS › AVS Forum › Display Devices › Plasma Flat Panel Displays › LG Plasma Panel tweaks for better blacks.