Avia and Plasma Screens (1 Viewer)

[Jaxon's Dad]

The Database problems that Parker talked about affected the thread I had started and it was deleted, so I'm reposting my initial post and the reply as well as my reply to the first reply. Anyone with anything to add, please do so.

Originally posted 06-17-03
I helped a buddy calibrate his new Panasonic PT-42PHD4-P Plasma TV using Avia. We adjusted the black level to the recommended specs, but when it came time to adjust the contrast and sharpness, it appeared that the default settings were sufficient. This also was the case with the color and tint settings. Figuring that the defaults would be fine since this is a plasma screen and not a CRT set, we closed out Avia and then demoed various selections from several different DVDs, finally ending with a screening of Monsters, Inc. During the screening, I noticed a few times the image seemed to flicker. This was particularly noticeable on the upper right frame of Roz's glasses, and there was one other time that the background behind Sully shimmered. I've read several reviews of this disc and the only complaint from any reviewer is that the image seems to be too soft. Nowhere does anyone mention this shimmering. So it makes me think that we may have missed something in the calibration. Could the contrast and sharpness be the cause of the image problem? Other non-Pixar discs appear to have a great image, but if tweaking will improve Monsters, Inc. then I can only imagine what other dvds will look like.

Thanx in advance.

D

Reply from Rick H on 06-17-03
Doug,

I'm not perfectly sure what you mean by "shimmering." I tend to use that term to describe the twinkling, pixelated look of a scaler when it is struggling with source material (as can be the case with some plasmas). Or are you seeing de-interlacing break-up of straight lines?

I have the same plasma. Using a Panasonic RP-91 DVD player, progressive scan output, I see no shimmering to speak of in my display. Are you sending the plasma a progressive scan output from the DVD player?

When I feed my plasma an interlaced signal (so the plasma has to do the de-interlacing instead of the DVD player), then I do occasionally see some de-interlacing artifacts that might be described as shimmering of fine details.

Yes sharpness can exacerbate any artifacting, such as shimmering. But I doubt it's a problem in this case.

(Personally, I think you can get an even better image out of this plasma from another method other than AVIA...but perhaps that's a topic for another time... )

Reply to Rick H on 06-18-03
Rich,

The phenomenon is more akin to twinkling and not de-interlacing break-up. I double checked with my friend and he's got a Philips DVD793C. Progressive scan is on and 3:2 pulldown is enabled. In fact he's got 3:2 pulldown enabled on both the plasma screen and the dvd player. He wasn't sure which to choose, so he played it safe. Should he pick one or the other instead of having both enabled?

Can you comment on his Digital Audio Out settings? His choices are:
1.Dolby Digital/PCM or Stream/PCM or PCM (He has Dolby Digitial/PCM selected); and
2.Sample Freq: 48 KHz or 96 KHz (he has 48 KHz selected).

By all means enlighten me on this "other method." I don't mind hijacking my own thread (See above... ), but feel free to start another or just email me or send me a pm.

Regards,

D

 

[Rich H]

Doug,

For a little bit of heresy on how to calibrate your Panny plasma, look at this thread:

Steaming Rat Method of Calibration

Surprisingly, the feedback has been all positive for those who have used it.

YMMV, of course.

 

[Rich H]

Hey Doug, any luck with that shimmering? I'm curious if you were able to trace the problem. Does it remain if you turn brightness (black level) and contrast down?

 

[Jaxon's Dad]

Currently, brightness is turned down per AVIA standards, and we will try contrast sometime this weekend. I'll post as soon as I know.

Any thoughts on my digital audio settings question?

 

[Jaxon's Dad]

Bumping this for 2 reasons:

1. UPDATE: My buddy tried adjusting contrast and sharpness with no change. Incidentally another title that displays this same type of problem is "Unbreakable," specifically the grill of Samual L. Jackson's car.

2. Anyone have any other ideas? I'm seriously considering a purchase of Digital Video Essentials.

 

[Rich H]

Have you tried brightness even *lower* than AVIA standards? Have you dialed brightness right down, watching the twinkling to see how/if it is affected? It at least might help diagnose the problem. Too high brightness will definitely bring a shimmering effect like what you describe (at least as I imagine what you are describing).

I cannot think of anything that Digital Video Essentials will do for you that you cannot do for yourself, with regards to this *particular* problem.

What I mean is, cranking down brightness will generally lower the noise in a picture. Same with contrast and sharpness. Have you tried dialing down the color? I actually find that color adjusted via AVIA remains too highly saturated for my taste on this display, and especially with plasmas this can bring out noise in the picture. Notching back the color saturation can therefore reduce the noise in the display. All these remedies are already in your hands, without need for a calibration disc to see if they work. If they are not working, then...well...I'm not sure what to say. Only that, when I used my progressive scan signals from my DVD player, the picture is very smooth on the whole.

That said, I've never seen a monitor that displays DVD after DVD totally free of artifacts. There is in fact quite a number of DVDs with their own mpeg artifacts, including pixelation type artifacts that would seem to fit your description. It doesn't sound from your posts that you are actually seeing this "twinkling" very often, am I right? If so, it may simply be within the bounds of any ordinary display, or maybe it's revealing some previously unnoticed DVD artifacts. The grill of the car in Unbreakable sure sounds like a de-interlacing artifact. But you will also see that type of artifact (grill break up)
sometimes as a consequence of the DVD transfer - mpeg artifacts, detail break up, pixelation etc. (I would check the Monsters Inc shots, but I have no idea to which shots you are referring).

 

[Jaxon's Dad]

Rich,

Thanx for your input. Brightness is dialed down pretty low as it is right now - I think it's at something like -17 or so. We'll see if we can get it down even lower and try dialing back the color too.

I'll see if we can get a chapter and time code of the specific scenes in Monsters Inc. so you can compare also.

Regards,

D