Join Date: Jul 2002
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|Originally posted by defed
ok, here's what else i noticed. when using component inputs of dvd (input 2), i used G. antenna input used 4. dvd thru composite (input 3) was also affected by 4.
dvd in 480p or 480i component (input 2) both used G, so im guessing its based on input rather than signal type alone, which i had thought was the case from the other posts, perhaps just my interpretation was incorrect.
have yet to see what F controls, for me its not component dvd like the others have used.
what inputs are ppl using for dvd when they use F for adjusting?
|Earlier I reported that the same settings seemed to work equally well on 1080i. I have been watching a few shows this evening (i.e. Katie Couric) and I now have to say that it still is not quite right. Using the same settings does reduce the red push somewhat but it is still there compared to the other inputs. At the same time, it seems to create a bluish hue in 1080i that just does not seem quite right. Note I am not using Avia or any definitive reference patterns, just my overall observations. Keep tweaking and sharing, I am sure that collectively we will nail those settings. Too bad someone from Hitachi does not join in the fun!|
|Originally posted by defed
One other thought. if grayscale is the neutral base upon which the color is added, adjusting the color decoder on top of a non 6500k greyscale is only a partial solution? more accurate, but not really accurate?
|I keep seeing this time and time again when people learn about red push problems, cut and drive controls in the service menu, put the two together in a flash of brilliance and try to fix red push by cutting down the amount of red using the red drive controls. Even if you are not currently thinking about doing something in the service menu, tuck the following tidbit away for later.
Grayscale and Color Decoding are Not the Same Thing
Do not confuse grayscale (aka white balance or color temperature) with color decoding problems like red push. You must not change controls for one to fix the other. I frequently read of someone trying to correct red push (excess reddish color in red color objects) by displaying color bars and turning down red drive to fix the red. If you are doing anything like that or are contemplating such a manuever, don't. You've fallen into the newcomer trap of confusing the amount of red in the grayscale with the amoutn of red in red colored objects. You've gotten grayscale and color decoding confused with each other.
The video image is basically a grayscale one upon which colorization is added. The color of the underlying grayscale is a specific ratio of red, green, and blue. That ratio ideally creates a color of gray known as D65. If you alter the cuts and drives of a display, you are altering the color of the underlying grayscale image. That grayscale must be kept completely neutral or else any tinting you create would affect all images. If you drop the amount of red you decrease the amount of red globally. Even things which are supposed to be neutral gray would lose the amount of red in them.
Chroma or color information is decoded and used to colorize the underlying grayscale image. The user controls saturation and hue adjust how color decoding is done. If you visualize it in terms of a color wheel. Saturation changes the intensity of colorization. Hue basically alters the angle of the color wheel used to assign colors. Color decoding which causes red push simply means that colors near red are intentionally overemphasized. Note that altering chroma controls does not change the underlying grayscale's color. It changes the colorization which is added.
So you see you have two very different things which shouldn't be mixed up.
The color of gray is examined using things which have no colorization like gray windows, ramps, and field patterns. The idea is to set the grayscale to a neutral D65 using the cuts and drives. Cuts affect mostly the dark end. Drives mostly the bright end. One uses a colorless test pattern because you don't want anything to change the on screen color except the color of gray. BTW, it is quite difficult to set grayscale accurately without some sort of instrumentation.
Color decoding is how the colorization information gets interpreted and then added atop the neutral grayscale image. The user controls can be used with color bar patterns to make adjustments. Color bars are useful because they contain fixed amounts of colorization which are equal for red, green, and blue (for each portion of the pattern that contains that color). Since the gray portion of the pattern has zero colorization but has a brightness of gray exactly composed of the amount of red, green, and blue which should be in the colored portions of the pattern. One can use the gray as an unchanging point of comparison as color decoding is adjusted. In some displays there are color decoding axis and gain controls which can be used to make a color decoder behave in a more NTSC standard fashion and eliminate red push. Not all sets have such controls.
If the difference between grayscale and color decoding is still unclear, try this analogy.....
You are in charge of art displays across the country and want to ensure that the art looks the same in every one of your galleries. To make that happen you choose a standard color of lamp (D65) for all your galleries.
Think of the color of gray (the grayscale) as the light of the lamp which is illuminating a painting. If the artist chose paint with too much red for faces (decoder has red push), a newbie art corrector could try "fixing" the excess red by reducing the red the lamp light. That would fix the excess red problem in faces but you no longer neutrally illuminate the painting. Everything would be badly tinted because you have changed the underlying white balance. That is what adjusting the cuts and gains does.
The real solution is to convince the artist to always use paints that actually look the right color under the neutral standard lamp (D65). That's basically what you do by adjusting the saturation, tint, and color decoder axes & gains correctly. You have selected paints which are the same color used by artists everywhere when they paint under a D65 colored lamp. This fixes the problem reds without ruining everything else.
A few artists still insist on using the wrong color of paint. In such cases you force the audience to stay in a bright red room to make them less sensitive to seeing red when they actually see the incorrtly colored painting (turn down the saturation). This hides the flaw, but doesn't really correct it.
I hope this makes it a little more clear why cuts and drives are not used to correct red push.
|Originally posted by Mfusick
I think that is probably against company rules even if they do monitor this site.
They don't want us messing inside the set either...
|Originally posted by Mfusick
Welcome to the club...
Here is some pictures, incase we need to compile further a tweaks post.
links don't work on my end :(
|Originally posted by RichUF
As you can probably tell, this is the first time I have ever been in a service menu of a TV...thanks for your patience if I got a lot of this wrong. Thanks to all, but expecially to MFusick, Ken Stokes, Prakash, and Amph for all of the great info over the last few months that led me to this great set!
|Regarding HDTV, my jaw has yet to drop with the possible exception of the Alabama/Auburn game on CBS last Saturday (first day with set). Why don't the primetime shows look as good? (so far I've sampled CSI Miami, Leno, and NYPD Blue). Dark scenes as opposed to out in the bright sun perhaps? I'm waiting to be impressed before showing the set off to friends for fear of potential "you paid $$$$$$ for that?" comments.|
|posted by inaka
|Originally posted by DYH
I have my interlaced DVD hooked up to input 1 and adjusting F did correct the red push. Spiderman and the red wedding scene from Crouching Tiger were much improved.
1080i is also improved from the same settings on G. Being able to increase the color has really improved the HD shows. I am waiting til Sunday's reruns to see how it affects Smallville as this show was almost unwatchable at times.
Thanks again for all of the great info!
|Originally posted by erick granato
me again-i bought the 51swx20b a month ago and love it. so any help to fix red push would be greatly appreciated