Originally Posted by puchall1
So what in a nutshell are you saying, crank the contrast for the flicker? What are your easy suggestions......for tweaking. Is this flicker here to stay?
Hitachi 55hdt79 BTw.
Based on your other posts I'm assuming you're referring to the fluctuating or floating blacks. I think CDLehner's probably pretty close to the mark in his last post.
Originally Posted by CDLehner
The image was entirely black, I pressed pause...which created an image of all black, with a white pause symbol in the upper right-hand corner of the panel. When the pause went away, and the white was eliminated from the image, the panel, UNIFORMLY, shifted its Contrast down; the whole panel went dark, darker, darker still, like 4 Contrast level shifts down , to account for the absence of the white in the image. IMO this has got to be by design, as it was too uniform to be a defect, and it makes sense as either an Auto Contrast feature, which I have heard this set may have, or as an inherent function of the ALiS panels (Alternate Lighting of Surfaces).
The contrast fluctuations are the most pronounced by far on my 42HDS69 with the Dynamic Contrast Mode
. So first thing I'd do is set that to Normal (if it isn't already). With the Normal Contrast Mode setting I get only minor changes in the black levels, and can only see them with relatively low or no ambient light. Being sort of new to the plasma game, I can't really be certain if these minor fluctuations are by design or not, but as CD mentions, they seem to act is if they are. It looks like they may be intended to elevate the blacks slightly as the average picture level goes up to make shadow detail more discernible, sort of mimicking the behavior of a CRT.
The problem I think many users are having, is that they're trying to watch their displays in ambient surroundings that are too dark. With a decent amount of background illumination, the fluctuations become all but invisible on my 42HDS69, and probably work more as they were intended. So my first couple of recommendations are:
1. SET THE CONTRAST MODE TO NORMAL RATHER THAN DYNAMIC.
2. INCREASE YOUR BACKGROUND ILLUMINATION.
(Try to keep as much ambient or direct light from hitting the screen as possible though, because that will just wash out the contrast.)
My guess is that doing those two things will cure the problem for most people, and it will also improve the sense of depth in the picture.
In terms of Contrast, I'd say just set that to a level that's comfortable for your eyes, given the ambient light in your particular viewing environment.
I'd probably turn off the Black Enhancement, on the outside chance that may contribute to the problem on some displays as well. All those settings really seem to do on the 42HDS69 is crush the black detail. And you can probably get about the same effect by simply lowering Brightness, if you want a little more color depth. (I've been tending to run it a little below THX Optimizer/DVE spec. But not too much.)
That leaves the Day/Night settings. On the 42HDS69, the Day-Normal and Night settings appear to be almost identical (if the other controls are set the same
). The Day-Normal setting seems to have a little more edge-enhancement, but that's about it. The Day-Dynamic
setting has more enhanced contrast, and it also seems to have the deepest black level, so black level fluctuations may be more noticeable in this mode than the other two. I think the Day-Dynamic setting was intended primarily for Showroom use. It's contrast enhancement may help on some darker scenes though, so it may be worth trying once your background lighting is set to a reasonable level. YMMV.
The only display I can really speak for is the HDS69 btw. So it's quite possible some of this may work differently on the HDT79.
Final note: Don't get the Contrast Modes and Day/Night modes above confused, since they use similar terms (Dynamic and Normal). The Day-Dynamic setting is possibly worth considering, but I would avoid the Dynamic Contrast Mode
(which is lower down in the video settings menu). I haven't noticed any pronounced fluctuations in contrast, just some minor "CRT-like" flotation of the blacks since turning the Dynamic Contrast Mode off (ie setting Contrast Mode to Normal), and increasing background lighting. Hopefully that's clear.