How To Set Contrast On A Plasma - 42" Panny

[meths]

I opted for the Panasonic TX-P42GT50B as a replacement for my broken Bravia LCD and have been trying to calibrate it tonight using the test patterns on my Digital Video Essentials Blu-ray.

All is going well but I'm maxing out the contrast control before the white patches start to bleed together on the test pattern and there is no noticeable colour tinge on the brightest parts either.

So I've just left the contrast turned up full and the picture seems fine for it with no blooming or the like.

It's my first plasma so I'm wondering is this normal to just crank up the contrast on these sets or am I doing it wrong?

 

[lucid]

What's the source device.... PS3 or BD player?

 

[inogen]

I was told by a Panny engineer on the phone the other day not to run brightness or contrast at over 50% for the first 6 months of use.

 

[imginy]

Turning the contrast setting up only increases the light output.

Basically the contrast setting on these panasonic plasmas is like the backlight control on an led tv.


You shouldn't move the contrast past halfway until your tv has had 100 hours use and after that there shouldn't be any reason to have it much past half way.

Basically if you need contrast set too anywhere near 100% your doing something wrong.


Out the box the colours are pretty good you shouldn't need to do much other than;
put it in true cinema mode
turn down sharpness
turn off vivid colour
turn off pnr

If your whites are still wrong try playing with brightness or gamma settings and check to see whether your blueray player is set too ycb444 or rgb.

 

[meths]

What's the source device.... PS3 or BD player?

PS3. I think you may be on to something here as I've always felt that the video playback from the PS3 was very dark compared to using other input sources either when streaming media or playing from disc and regardless of which TV I was using.

I think it may be incorrectly displaying the pluge pattern causing me to set the brightness too low which in turn is making me try to ramp up the contrast to compensate.

Turning the contrast setting up only increases the light output.

Basically the contrast setting on these panasonic plasmas is like the backlight control on an led tv.


You shouldn't move the contrast past halfway until your tv has had 100 hours use and after that there shouldn't be any reason to have it much past half way.

Basically if you need contrast set too anywhere near 100% your doing something wrong.


Out the box the colours are pretty good you shouldn't need to do much other than;
put it in true cinema mode
turn down sharpness
turn off vivid colour
turn off pnr

If your whites are still wrong try playing with brightness or gamma settings and check to see whether your blueray player is set too ycb444 or rgb.

That's pretty much what I've did so far although I think I'm leaning more towards THX Cinema - Bright Room as opposed to the normal THX Cinema mode.
It's basically a trade off between light output and having ever so slightly washed out colours although it might just be that the plasma is giving off richer colours and an overall darker picture than my old LCD and my eyes just aren't used to it yet.

TBH there's hardly any difference from having contrast at 50% compared to 100% under normal viewing conditions.

 

[Kei]

Brightness on these sets is not like an LCD panel. It adjusts the level of black, leaving whites unaffected. Easiest way to set the brightness level is to play some 4:3 or letterboxed content and turn the brightness up until you see dithering (random dark coloured pixels) in the black bars, then drop it back a notch. (You need to view quite close)

Contrast controls the white level, but don't forget that a mostly white screen is automatically dimmed by the set to avoid overheating the panel. You can download the AVS test disc files and run them via your PC. I set my UT50 plasma up to the correct settings straight from the day i got it and have run it like that for 3 months without any IR or burn issues. (I watch a lot of 4:3 & letterbox stuff too)

I run a pixel format of 4:4:4 and for reference my contrast is set to 13 notches down from maximum.

 

[lucid]

PS3. I think you may be on to something here as I've always felt that the video playback from the PS3 was very dark compared to using other input sources either when streaming media or playing from disc and regardless of which TV I was using.

Yep. I've professionally calibrated more Panasonics than I can recall. I've never had one that wouldn't set contrast correctly when using my test pattern generator. Any issues have usually been to do with the source device or some intermediary bit of kit such as the video processing in AV amps.

I'll bet that you've probably got the PS3 set to "RGB Full Range" rather "Limited". And why wouldn't you? It sounds like the right thing. You want the "full" of anything, surely??? What they don't tell you is that it messes up the contrast and brightness mapping for any video based material. It would be better named Video instead of Limited and Game for Full.

Set the PS3 to "Limited". You'll notice that the brightness changes significantly. Set that correctly first before doing contrast. The blacks will probably appear a little brighter than you are used to but don't worry, that's correct. What you should then have is better shadow detail. You can always crush a little of that black detail if you prefer exaggerated black level. Now if you go to the contrast setting you should find it will be possible to over-saturate.

As a quick check you can use the crossed ramps pattern. There's some marker lines three steps in from the left and right sides of the screen edges. These show you the correct dynamic range for video (16~235). The whole pattern shows the PC dynamic range (0-255) which isn't correct for video.

 

[Psycho Sonny]

aren't you supposed to leave them stock until the screen has run in before adjusting / calibrating?

also the GT50 out of the box is supposed to be the best tv on stock settings, this doesn't mean it doesn't need calibrating, but it needs less than your average tv.

if you do not know what you are doing leave it at stock. otherwise pay a professional £200-£300 for a calibration. if you cannot afford or justify a calibration then just leave it. you need a colour level monitor in order to do a proper calibration, all you are doing is adjusting to suit your own eyes in the current light setting.

do bare in mind the environment has a huge effect on calibration, therefore if you watch movies with the lights off and the curtains closed, your adjustments will be wrong for this scenario, if you adjusted during the day with daylight, etc.

also if you move the tv from one room to another, it would need re-calibrating.

basically just stop messing about with the tv and just enjoy it, you will never get a reference picture without a professional calibration.

 

[meths]

aren't you supposed to leave them stock until the screen has run in before adjusting / calibrating?

also the GT50 out of the box is supposed to be the best tv on stock settings, this doesn't mean it doesn't need calibrating, but it needs less than your average tv.

if you do not know what you are doing leave it at stock. otherwise pay a professional £200-£300 for a calibration. if you cannot afford or justify a calibration then just leave it. you need a colour level monitor in order to do a proper calibration, all you are doing is adjusting to suit your own eyes in the current light setting.

do bare in mind the environment has a huge effect on calibration, therefore if you watch movies with the lights off and the curtains closed, your adjustments will be wrong for this scenario, if you adjusted during the day with daylight, etc.

also if you move the tv from one room to another, it would need re-calibrating.

basically just stop messing about with the tv and just enjoy it, you will never get a reference picture without a professional calibration.

I've read conflicting things on whether you need to leave the panel for x amount of hours before adjusting anything. Some sources say you do and others others say it doesn't matter as much as modern plasmas are less susceptible to permanent image burn.

Also I'm not going to pay £200 to get a £750 tv calibrated but I think I've paid enough to be able to mess about with the settings a bit.

All I'm really wanting to do is check brightness, contrast and that the colour is in the right ballpark using a filter that came with my DVE bluray. I'll be going for one set of settings that suit most scenarios and not trying to fine tune it for all lighting conditions.

This thread really just came about because I thought something must be up as even with the contrast up full the whites came nowhere near the point of over-saturation.

I think lucid has hit the nail on the head in his post and that'll solve my issues.

 

[lucid]

I think lucid has hit the nail on the head in his post and that'll solve my issues.

Do let us know how you get on

 

[Psycho Sonny]

I've read conflicting things on whether you need to leave the panel for x amount of hours before adjusting anything. Some sources say you do and others others say it doesn't matter as much as modern plasmas are less susceptible to permanent image burn.

Also I'm not going to pay £200 to get a £750 tv calibrated but I think I've paid enough to be able to mess about with the settings a bit.

All I'm really wanting to do is check brightness, contrast and that the colour is in the right ballpark using a filter that came with my DVE bluray. I'll be going for one set of settings that suit most scenarios and not trying to fine tune it for all lighting conditions.

This thread really just came about because I thought something must be up as even with the contrast up full the whites came nowhere near the point of over-saturation.

I think lucid has hit the nail on the head in his post and that'll solve my issues.

I have a 50" GT50 arriving tomorrow I got it price matched for £810 with free 5 year warranty. I also had £105 worth of vouchers (gift), so total cost of TV is £705 to me. I looked into calibration, etc and found that unless your using a monitor there is simply no point, professional calibration costs a lot of money and it needs to be done every time the environment is changed, therefore imo it's only worth doing if you DIY it by purchasing your own equipment and software than calling someone in every time.

I also looked into BIAS lighting and ordered a kit for £25, this will help improve image quality and stop eye fatigue, this is as much tinkering I will do and just keep the set at stock.

I do have some generic settings to try from AV forums which have been considered to be good from a lot of different members, these aren't in dept settings but more reducing the overpowered greens the panels have across the board.

Also there are far better ways to adjust contrast and brightness, those THX test's on Blu_Ray's aren't as in depth as the ones people over at AVforums use that do not want to spend money on a calibration or a calibration is not possible.

I may look into these in further depth after my set is run in, all professional calibrators recommend running a plasma in before calibrating. They do change with time, it's not for retention reasons.

 

[imginy]

I've read conflicting things on whether you need to leave the panel for x amount of hours before adjusting anything. Some sources say you do and others others say it doesn't matter as much as modern plasmas are less susceptible to permanent image burn.

They definitely run hot for the first 400 or so hours and this is when you are most likely to get an image permanently burned in.

Most people will run colours slides for the first 100 hours to break the colours in before they calibrate.

Picture quality gets better over the first few hundred hours as well

 

[meths]

I have a 50" GT50 arriving tomorrow I got it price matched for £810 with free 5 year warranty. I also had £105 worth of vouchers (gift), so total cost of TV is £705 to me. I looked into calibration, etc and found that unless your using a monitor there is simply no point, professional calibration costs a lot of money and it needs to be done every time the environment is changed, therefore imo it's only worth doing if you DIY it by purchasing your own equipment and software than calling someone in every time.

That's a great deal on your set.

My tv cost me £25.

They were going to give me it for nothing with a 1 year warranty but I talked them into letting me pay £25 to extend the warranty to 5 years. Plus I managed to get in on the Panasonic promotion for 2 free sets of 3d glasses just before it expired on the 31st March. They're still selling those ones at £60 each so all in my tv cost me -£95.

Point taken about the settings. I'll look into setting up some colour slides to run when I'm out of the house over the next few weeks..

 

[Psycho Sonny]

That's a great deal on your set.

My tv cost me £25.

They were going to give me it for nothing with a 1 year warranty but I talked them into letting me pay £25 to extend the warranty to 5 years. Plus I managed to get in on the Panasonic promotion for 2 free sets of 3d glasses just before it expired on the 31st March. They're still selling those ones at £60 each so all in my tv cost me -£95.

Point taken about the settings. I'll look into setting up some colour slides to run when I'm out of the house over the next few weeks..

I wouldn't bother running colour slides tbh your just wasting electricity. Use the tv normally, and just check for retention every day using the scrolling bar, keep gaming and logos and black bars to a minimum too for the first 400 hours.

After 400 hours you can then adjust the tv using the methods over at avforums.

There is also a chance of the slides getting stuck, so imagine leaving it on a "red" screen for 2 weeks, you could ruin your set.

 

[meths]

Ha! Reset the settings and stuck on a film on loop from my media server when I went out earlier and the bloody thing went into standby automatically.

 

[Psycho Sonny]

Ha! Reset the settings and stuck on a film on loop from my media server when I went out earlier and the bloody thing went into standby automatically.

hope there is no black bars in said film, also you need to disable power saving, etc then.

 

[meths]

Do let us know how you get on

Had a play with the TV again last night and observed the following:

-The PS3 was set to RGB Full and the set needs Limited.

-The video signal was defaulting to YCB and not RGB and when manually switching to RGB it looks like some white information is being clipped. I left it set to YCB.

-THX Cinema mode is severely limited in terms of light output and to calibrate to reference standard you have to use the Professional Mode - from various reviews of the panel.

-In order to get the top range of white to bleed into beyond white on the test pattern I have to up the gain setting on the gamma in professional mode. I can then dial back contrast normally to the point where white and beyond white separate.

So I think the plan for now it to leave the set in THX Cinema Mode for a couple of months until it has bedded in and then calibrate it in Professional Mode. Either that or I'll just leave it a couple of months and then ramp the contrast up in THX Mode to a level that I find acceptable.