White clipping question

If you then raise it by one click and 253 stops flashing, you are at the max contrast setting with the maximum head room. If one more click does not change anything, you are not at the proper setting

Make sure you go back and check brightness as they do interact.

You are better off leaving a click or 2 lower than having discoloration

Once maximum contrast is found use the color clipping pattern to check that RGB is not being clipped.

you lower the contrast till no colors clip.

No you are done, just recheck brightness as contrast and brightness interact.
Your PS3 was not set up correctly to pass BTB and WTW.

These are the settings for ps3 to use for video
Video Settings

BD Internet: "Allow"
BD/DVD Cinema Conversion: "Automatic"
BD/DVD Upscaler: "Normal"
BD/DVD Video Output Format (HDMI): "Y Pb/Cb Pr/Cr" for TVs, "RGB" for PC Monitors
BD 1080p 24Hz Output: "Automatic"
BD/DVD Dynamic Range Control: "Off"
BD/DVD Audio Output Format (HDMI): "Linear PCM"
BD/DVD Audio Output Format (Optical Digital): "Bitstream"

Display Settings

RGB Full Range (HDMI): "Limited"
Y Pb/Cb Pr/Cr Super-White (HDMI): "On"

None of this means that 98 or 99 or 100 is the RIGHT SETTING. The right setting is much more difficult to arrive at... much more complex, and it really requires a meter to determine how the TV performs with different Backlight settings so you can find the Backlight setting that produces the best images. Sometimes that's the lowest Backlight settings because the blacks will be darkest. Most of the time, though, the Backlight goes funky at lower settings and you may have to use a few clicks or more above the lowest Backlight setting.

The RIGHT Contrast setting might end up being 50 or 63 or 77... you just don't know because you can't determine where the Backlight should be set.

The test/setup discs only help you find the highest possible Contrast setting you can use without losing steps. The CORRECT Contrast setting depends on using the optimum Backlight setting and not having any eyestrain issues when you view the TV in a dark room. The accepted range for 100% white in a dark room is 30-35 fL. You might be producing 80 fL with Contrast set to 99... that's so bright you will have eyestrain issues in a dark room. The problem you have is that without a meter, you don't know whether you are at 80 fL or 50 or 32. All you can do is view TV programming or a movie for 2 hours or more than take note of whether you detect any eyestrain. If you do, reduce the Contrast setting, maybe 5 clicks, and try again. Keep repeating this until the feeling of eyestrain is gone.

There is no way to predict the proper Backlight and Contrast settings in advance. They are different for different brands and models.

Doug is simply referring to the fact that for many display types contrast is linked to light output.

And in most environments maximum light output will cause eye fatigue, so in those cases you would want a contrast setting even lower than the point just below clipping.

Use the settings above for your PS3 and connect it directly to your TV, some receivers are known to do that.

Even if you can isolate the problem, it's unlikely you can fix it, if the receiver is clipping. You'll just have to live with it. Clipping at 235 isn't a huge loss in picture quality.

No that's not a problem, if contrast at 100 is good enough just leave it there.

Assuming we are talking about LCD flat-panel displays with a Backlight control, the highest Contrast setting that doesn't cause clipping or discoloration (at either 235 or 255) is generally (but not always) the right setting unless you don't want to maximize the dynamic range/native contrast ratio of the LCD display. The Backlight control can then be set to a comfortable light output level ideally with a meter or if no meter is present by eye to a level that looks bright enough without causing eyestrain when watching the TV for several hours or more.

On the LCD displays I've owned and calibrated the correct backlight setting for a dark to dim room is usually 33% to 50% of the maximum value. The bottom line is if the test pattern (white clipping pattern in this case) shows that 98 is the correct value (or highest correct value to be more exact) then that value should be used in conjunction with a backlight setting that produces a light output in the target range (say 30-40 fL for a dark room). Using a contrast setting like 50 would greatly reduce the dynamic range/native contrast ratio of the LCD display and result in a more washed out picture with a much higher MLL. Why use a lower contrast setting than necessary unless it's one of the rare cases where the display forces you to use a very low backlight setting (near minimum) and that somehow messes up the grayscale/gamma/gamut?
Edited by PlasmaPZ80U - 12/6/12 at 10:58am

^^^

Because the Backlight controls how dark or light the blacks are.... increase the Backlight setting and you increase the black level. Black level has more influence on Contrast Ratio than the white level. So you want the Blacks as dark as possible (lowest possible Backlight setting). After you determine what that setting is, you then set the Contrast control to achieve 30-35 fL for dark room viewing. In other words, reducing black level by 10% improves contrast ratio more than raising the white level by 10%. Example: white level 35 fL & black level .035 fL = contrast ratio 1000:1. Raise white level 10% to 38.5 fL... new contrast ratio = 1100:1. Now put Contrast back so that white is at 35 fL and reduce the black level by 10% to .0315 and the new contrast ratio is 1111:1, an 11.1% better result in Contrast Ratio improvement than you get from raising the Contrast setting to get more light output.

And... if you had a PERFECT video display with blacks that were ZERO fL, your contrast ratio would be infinity no matter what your Contrast control was set to. In that case, the ONLY consideration for the Contrast control setting would be a setting that minimized or eliminated eyestrain and we know that is in the range of 30-35 fL for panel displays in dark rooms.

Emphasizing contrast ratio improvements by raising the Contrast control setting tends to push viewers into eyestrain territory... it doesn't hurt your vision, but it is uncomfortable for no reason.

You cannot say that "most" LCD displays do any one thing or another because they are all over the map.

You can't really be sure you have found the lowest-possible "good" Backlight setting without a meter to tell you what is happening with color measurements and other properties since linearity problems may become invisible to your eye rather quickly... that doesn't mean the problem doesn't exist, it just means it's difficult to pinpoint the problem by eye -- which is why we use meters for calibration instead of eyes.

Basically maximize contrast and then use backlight.

You want the lowest backlight you can use to get the fL you want. That will also give you the lowest black level. Backlight usually increases and decreased White level and Black level by the same amount, so you can't really maximize contrast ratio with backlight, you can maximize it with contrast. Which is why for LCDs their is one correct contrast setting, it's not a negotiable thing.

Then use the backlight to get your targeted light output.

Use the visual pattern to set contrast to the highest point where it looks right.
Set Backlight to whatever seems comfortable for the room.

If you don't have a meter, stay away from the white balance section.

The problem is that you just can't pick a low Backlight setting... the backlight produces a spectrum of light... there are different amounts of all colors of light (every color has a different frequency). The spectrum of the light can change a lot, especially at very low Backlight settings in SOME TVs. You will not know if this is happening without a meter to measure the response of the Backlight at lower settings.

Without a meter, I would recommend setting the Backlight control higher than the lowest setting... if the control range is 0-10, I would probably use 2 or 3 for the Backlight setting then set the Contrast control to get a comfortable light level in a dark room (no eyestrain after 2 hours of viewing). BUT.... what if the TV will not produce 30-35 with a contrast setting of 99? Then you have to raise the Backlight control. BUT... you won't know if the TV is higher than 30-35 fL or lower than 30-35 fL unless you have a meter. So when you do not have a meter, you are guessing and it is very difficult to determine the combination of Backlight and Contrast setting that gives you the best black, the right amount of light for white in a dark room... AND the Backlight setting has to be high enough to not cause color problems (or other image quality problems).

This is a complicated situation -- none of the test/setup discs explain this clearly and all of them give you instructions that only help you find the highest usable Contrast setting... not the BEST Contrast setting (nor the best Backlight setting).

This is one of the reasons that calibration is such a popular subject on AVS Forums.