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Just got HD7, excellent. But I have a question or 2....

Discussion in 'Plasma TVs' started by charker, Nov 26, 2004.

  1. charker

    charker
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    Just received a Panasonic HD7 screen from AVSales (they got some stock yesterday) and have rigged it up with s-video for now using the 2-slot (composite, svid, component) board

    First the picture looks fantastic (DVD and SKY), with one slight reservation. When the screen is completely black, the top right segment (a 3rd of the screen horizontally and half the screen vertically) is brighter than the rest of the panel.

    If you turn the contrast down to +10 instead of +30 it goes away. Is this normal? Can segments of the display be tweaked through engineer menus etc to bring them into balance? It looks as though the panel is made up a 6 segments and one is a bit too bright.

    For anyone wondering, SKY+ through Svideo looks fine, as does DVD. Wondering now just how much better RGB/Component could be!

    Next I have another question about my amp, a Denon 3300. It switches "component" (it does no upgrading of signal s-vid to component etc) and I wondered will it switch RGB instead cos' everything I have is RGB. I just wondered before I splash out on expensive SCART to RGB lead to try my theory.

    I'm Just thinking of rigging RGB from DVD and SKY into my amp and then up to the screen. Damn DVD does do component! A new progressive one is next on the shopping list.

    CHarker
     
  2. guli

    guli
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    you just received it and running it at +30 contrast?

    good for you! (shock horror)

    I have no idea about the different brightness, but I think contrast of +10 is STILL TO HIGH

    Alex
     
  3. Chris5

    Chris5
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    unless, of course, the set really is faulty
     
  4. charker

    charker
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    Guli

    That +30 is the factor setting (well +25 actually I think) it came out of the box with. We are talking contrast here, not brightness which defaults to 0.

    I was looking on the AVSFORUM site and they have a thread with settings for "7" panels. They quote 25 is the factory default and then people have tweaked them down to between -10 and +8.

    I did the THX setup thing on the NERO DVD but contrast is a bit dodgy, you can see all the squares no matter what the setting. The other screens set brightness and sharpness but these are similar to factory settings.

    I have ordered a setup disk from Amazon, but I have a 2 week wait until they have any. I will set the contrast to 0 and see how it goes.

    What about this brighter "segment", any thoughts?

    Charker
     
  5. charker

    charker
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    I have wound down all the settings as it seems most people recommend "running in" at lower settings. Why is this not mentioned in the manual anywhere and why would it default to a setting so high?

    The picture is quite watchable (if not a little dark!) on the lowest settings for brightness and contrast. I'll run it in for 100 hours or so and then move them up and wait for my settings disk to arrive.

    Does that sound reasonable?

    Would still like to know about my bright segment though!

    charker
     
  6. Mojito

    Mojito
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  7. charker

    charker
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    Mojito

    I actually posted a similar link a couple of weeks ago when I first read the same threads in AvsForums.

    No I'm not getting that type of effect really. I have not seen the "blooming" effect. I also get it with svideo and component connections which I tested with an older Pioneer 515 (region free model with 3 RCA component out)

    With brightness and contrast turned up (factory defaults) it look like my screen is made up of 6 carpet tiles arranged 3 across and 2 up and the one in the right upper corner is 3 tones of grey lighter than the other 5.

    So the top half of the rightmost third of the screen is lighter than the rest but "only" apparent when displaying plain black.

    Turning down contrast and brightness removes the problem.

    charker
     
  8. Mojito

    Mojito
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    I was following that long thread in AVS and some people who had problems desribed there were also having a problem similar to yours. I therefore wanted to know if you had any other problems that they were having. It's a kind of relief to know that you tested the s-video input and your screen is Ok as I'm also looking to buy Panny 7, but that AVS thread got me really worried.
     
  9. charker

    charker
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    You have started me looking now.....

    I just had a really wierd one, just like described in that post.

    Adjusting the brightness. I step up and down one value at a time and on the values 2 and 4 I get vertical bands of "snow/noise" coming down from the top of the screen. On 1, 3, 5 and all other settings they don't appear.

    This ties up with the comments about brightness going up and down as you decrease the values. Some digital processing screwing up.

    The bizarre thing is this svideo feed comes from my amp. My DVD recorder and DVD player (both panasonic) have "static" blue logo screens when they are not playing. Both are connected to the amp with svideo yet only the DVD Recorder feed causes this.

    Very odd. More investigation needed.

    Charker
     
  10. Gussie

    Gussie
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    charker have a look at http://www.lakemercedcoc.org/plasma/ and see if your problems are similar.

    This issue with the 7 series Panasonic panels now has me worried :rolleyes:

    The new thread http://www.avsforum.com/avs-vb/showthread.php?threadid=474833 in the US hopefully will result in some firm conclusions.

    One thing's for sure - I'm not spending a penny on a 7 series panel until this is sorted !

    Maybe I'll just grab one of the last 6 series panels instead - there's always something to ruin your plans !

    Gussie
     
  11. charker

    charker
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    I do have to add though, that under normal viewing the picture is fantastic, it's only when you start calibrating or analysing static logo screens that any of this is apparent really.

    Awaiting Panasonic replies with interest

    Charker
     
  12. Chris5

    Chris5
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    doesn't the avsforum stuff say that the problem is also there with series 6 to 4 as well, if this is the case, then there is nothing to worry about as we all know the good provinence of these older series
     
  13. charker

    charker
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    Yes, some claim these side-effects exist in all Panasonic panels going way back.

    I noticed that bringing up the "display settings menu" makes the black-bars (top and bottom) get brighter and then they go back to normal when you turn the menu off. Like the menu is "bright" and internal reflections (in some way) make the bars become lighter.

    I have noticed on s-video (I don't have a component setup yet) that you do get interference (like white noise) in the black-bars occasionally (depending upon how bright the rest of the picture is) but at normal viewing distance you don't really notice it.

    My main concern is this brightness (or is it contrast, I forget) which gets lighter and darker as you change the settings in one direction. I could see the white noise in the black bars on setting 2 or 4, but it wasn't there on 1,3, or 5. This is because 2 and 4 are brighter than either 1,3 or 5!

    I wonder if the screen is doing some kind of automatic brightness/contrast changes to keep the overall balance constant and the algorithm they are using is a bit flawed. Perhaps plasma screens have inherent characteristics which mean that as a picture changes content the settings have to change accordingly, like auto exposure in a digital camera. Just a thought.

    Even with the flaws, the picture I'm getting through svideo from SKY+ on this HD screen is brilliant, and I can only describe the picture I get from "pure digital" content (like Pixar animation, Bugs life, Toy Story and especially Monsters Inc) as breathtaking, better than anything I have ever seen in a shop demo (which are generally SD models) by a factor of 10!

    Charker
     
  14. Pottsy

    Pottsy
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    I'll just add my bit here....

    Just got my HD7 from AV-Sales, and it is utterly amazing. Have tried to reproduce the faults on those threads/sites and have failed to.

    For the moment, I'm using a scart input board and the output from my Pace Twin is very good (waiting for my Iscan HD+ to arrive). The only complaint is a tiny amount of "ghosting" on text - and this is generated by the scart board, because it still shows up when you zoom in.

    NOTICE TO DEALERS:

    If you want to sell these HD7's by the truck load (and you have a showroom), simply connect it to a PC and have some windows media 720p stuff playing as demo material. Totally and utterly amazing.

    This screen is capable of an incredible picture, it's just the crap that we throw into it that's the problem...
     
  15. charker

    charker
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    Glad you like your screen, as I have said it is capable of amazing pictures.

    Have you tried s-video and then play with the brightness and contrast to see if the black bars stay black and don't get "grainy" when the picture on display contains bright scenes?

    I was watching an interview and the guy was wearing a black shirt. As you tweaked the contrast the creases in the shirt appeared and disappeared depending on the contrast.

    You would expect the creases\shadows to appear as the brightness increases. The odd thing is that the shadows are visible on 1,3,5 but disappear on 2,4. Meaning the brightness dropped from 1,2 and 3,4 which is just plain wrong.

    Coincidently the "odd" brightness values are the same values that produce "grain" in the black bars.

    I can not understand why "garbage in" would produce grainy black bars when the circuits should just be sending "off" to every dot on both black bars no matter what "crap" is contained in the signal. This must be internal interference surely

    Charker
     

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