Monitor Display Overscan..Whats yours?

Discussion in 'Displays' started by TomTom, Nov 15, 2005.

  1. TomTom

    TomTom Agent

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    I was just curious if the overscan on displays are adjustable or not.

    My Panasonic & Sony CRTS at home look to average about 10% with DVD essentials dvd.

    Is your CRT about this?

    Are the DLP's, Plasma's and LCD's less or about the same? Or can you tweak it?

    I'm just trying to see if the overscan standard has changed at all recently.

    Thanks,
    Tom
    NYC
     
  2. John S

    John S Producer

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    10% is pretty high, mine was calibrated professionally to about 5% on my Philips 60".....
     
  3. ChrisWiggles

    ChrisWiggles Producer

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    there isn't really a "standard" defined for overscan that I am aware of, it's more a common practice result in the real world from CRT days which obviously continue today. In my opinion as little overscan as possible is best, though I'm a FP guy so I can get pretty much 0% overscan. With consumer sets there are some other considerations, but 5% is a good "regular" amount that you can shoot for which is usually less than a lot of consumer TVs have out of the box. Digitals don't really have the same need for overscan, data outside the picture range is usually just not displayed, it's a little difficult to draw a direct comparison to CRT overscan since there is no "scanning" occurring at all.
     
  4. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    5% is considered to be safe. Most sets do not allow you to adjust this in the user section. A select few permit it in the service section.

    Going to 0% is a bad idea ... since not all TV channels are actually centered.

    I usually shoot for 2-2.5% where permitted.

    Regards
     
  5. Tim Jin

    Tim Jin Supporting Actor

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    Michael,

    Since you are a pro ISF and since you know the Panny 47 RPTV so well, I hope you don't mind if I ask question about an overscan.

    I've noticing, since Good Morning America has gone to HD, the stock tracker on the right side of the screen is being cut off by overscan. The last digit where they show the dow jones is being cut off.

    I don't watch GMA, so it is not really a big deal, but it is still bothering me.

    When I check the overscan with Avia, I am right or little more than 5%.

    I went into the service menu and tried to check, but got afraid since Gregg calibrated my TV and did not wanted to mess things up.

    Could you please tell me where should I go to adjust the horizontal overscan?

    I think that I just need to adjust the overscan, just under 5%.

    Will I need to converge the TV again, even if the overscan is just minor?

    Thanks!
     
  6. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    There is a parameter called HWID or something like that. That will squeeze the image in a bit. A wee bit of overscan adjustment usually does not do enough negative changes to the overall convergence for it to matter. Just throw the fine grid up and take a look.

    Worst Case ... you have to touch up service convergence a bit.

    Regards
     
  7. Tim Jin

    Tim Jin Supporting Actor

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    Thanks!

    I will give it a try when I'm brave enough. Probably today or whenever.
     
  8. Tim Jin

    Tim Jin Supporting Actor

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    Thanks again Michael!

    I just adjusted my overscan.

    The right side is under 5% and the left side is at 5%.

    I still need to touch up the convergence, but it's isn't too bad.

    When doing the convergence, should I tune to an HD channel to do the 1080i and switch to DVD to do 480p/i?

    Thanks again!
     
  9. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    Yes ... tune to a 1080 channel when doing HD grid ...

    Did you want to do image centering now? HPOS does that ... or shifting the entire grid in the corse mode also does that.

    Regards
     
  10. Tim Jin

    Tim Jin Supporting Actor

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    That was my next question on how to center the image to get the overscan right under 5% on both sides.

    When I do the 1080i convergence, do I need to do the 480i/p also?

    How do you get the 480i/p grid up for convergence, DVD player?

    Do I need to do the 480i convergence also after I do the 480p?

    If I recenter the image, should I use Avia overscan test pattern, or should I DVR a show and adjust the centering and overscan from there?

    By tweaking with the overscan, centering and the convergence, will I mess up the grey scale and color balance that Gregg worked so hard to do?

    Again, thank you so much for the tips.

    I hope to see you and Gregg in Vegas for CES 06.
     
  11. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    480i/p should share the same convergence grid. 1080i has its own.

    480i/p grid is brought up the same way 1080 is brought up. Fine mode. It simply depends on what the background signal is at the time.

    Best to use the AVIA centering as a starting point. Make sure the DVD stuff is centered first. Unless the stock ticker takes priority over all other things.

    No ... will not mess up grayscale given the minor work you are doing. Don't worry about that.

    Both of us will be there in VEGAS at CES in January. Catch us being thown out of the various booths like the Sencore one ... the DWIN one ... the Runco one ... the Samsung One ... [​IMG]

    Don't miss our 10 round tag team fist fight with Eliab and Chuck Williams. [​IMG]

    Regards
     
  12. Jesse Skeen

    Jesse Skeen Producer

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    Do 16x9 sets have separate adjustments for the 16x9 and 4x3 modes, or does one setting affect both of them? I still have a 4x3 adjusted for as little overscan as it's capable of, when I finally upgrade I'd want to be able to do the same on the new set.
     
  13. Tim Jin

    Tim Jin Supporting Actor

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    Ahhh, talking to an expert is always a plus.

    That make sense when you mention about the type of singal that you have on at the time.

    Since 480i/p shares the same gride, I assume when I converge one of the input, I don't have to go back converge the other one?

    If I recenter the image with Avia, I assume that I should recenter first, adjust the overscan and then the convergence?

    Sorry for asking so many questions. I just want to make sure before I dive into tweaking.

    I am just hoping that the convergence will be minor after I recenter the image and get in under 5% on both sides.

    I tend to kick the remote off the table [​IMG]. Inside joke if you met me before.

    Your counter part will know of what I mean .

    See you at CES!
     
  14. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    In all the RP 16:9 sets I have encountered, the 4:3 mode was always based on the 16:9 convergence grid. Usually scaled off the FULL mode grid.

    Center first ... adjust overscan to desired (where possible) and then converge.

    I recall that the 47" units had some red convergence anomoly at the top right corner preventing the reduction of the top overscan by more than 5% or so.

    Regards
     
  15. Kevin C Brown

    Kevin C Brown Producer

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    One thing I noticed, on my Tosh 32" CRT overscan was different between the component video inputs and the composite. Because I care more about it for DVD, I adjusted for the component video input.
     

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