I’m near the end of what I can reasonably do as a somewhat engineer-geek homeowner who doesn’t have any specialized equipment for calibration. The last thing I’d like to nail down for a Sony 40XBR2 LCD and a Mitsubishi LT-46133 LCD is contrast. I’ve been using the DVE calibration disc and I also have the Monster ISF disc.

To my eye I can’t spot any issues with white clipping on the Monster white shirt scene or the DVE grayscale scene. I also don’t see any tinting going on. So my first reaction is to set contrast at max (since that’s what the disc instructions imply), or maybe back it off 5% just because max always sounds like overkill.

On the other hand, there are professionals in here who (if I may take a little liberty with the prose) basically suggest setting contrast “as low as you can stand it consistent with good picture quality”. I will admit it's quite possible that there are problems going on with my sets at max contrast that my eye is not trained or talented enough to recognize.

So ok, now I’m really confused. Set it high because there’s nothing in the test pattern performance to suggest otherwise, or set it low because of some other reason that I've never seen a good explanation for? If anyone could clarify I’d really appreciate it. Thanks in advance if you can help.

On your DVE disk, bring up a grayscale steps or ramp pattern. Turn contrast up very high, or all the way. Look to see in the brighter part of the ramp, if there is any color shifting (usually pinkish). Turn down contrast from there until it seems like it's completely gone off the scale. Then turn it down one or two more clicks just to make sure!

Next use the backlight control available on all LCD's I know of and turn it down to its lowest setting.

This is the point where I personally would start to watch familiar material, not patterns!

What do the white scenes and clothing look like? Are they white? Grayish?

If whites don't seem bright enough after a bit of viewing, dial up the backlight control until they do. Do NOT touch the already set contrast. Just use the backlight!

The idea is you already (hopefully) avoided white clipping and color shifting by using the grayscale patterns. Now just use the backlight control and set it as LOW as possible, while still getting satisfactory whites! It'll also help your black levels too to have it set low!

Now after all that, if when watching a movie you get eye strain, then you need to dial down your contrast or backlight more, because even if it looks good, if it hurts to watch it, it's really not that good after all! :)

I would also suggest getting a bias light (preferably an Idealume :D ) and viewing in a darkened enviroment.

One last note, make sure you do your adjustments in the enviroment conditions in which you plan on regularly viewing your LCD's!

Hope it helps, and good luck!

-Brian

As kamui says, display the grayscale ramp pattern with the steps. Lower you contrast significantly and then while watching the white all the way on either end keep raising contrast until you see it slightly change color. Back off until it goes straight white again. Keep in mind by "change color" we mean a slight shift. It's not going to turn bright blue or anything like that. The little dots you see at the black and white ends of the ramp are the 0% and 100% marks. Anything below the dots at the black end should be the same color as the black box on the other side of the dots. The white end you most likely will have no control over other then to watch for color shifting. Once you have brightness and contrast set this way, your TV should be at it's maximum contrast ratio.

The correct way to dim the picture to something reasonable to look at is with the backlight control as opposed to using the contrast control. So once you follow the above directions, just adjust the backlight to what you find suitable.

OK, thanks to both of you. I'm having trouble detecting any coloration of the upper end whites even at max contrast, but I'll go sit 4' from the TV tonight and see if I can detect anything. I guess I will just ignore the advice out there that talks about setting contrast as low as you can. Must be a CRT calibration thing.

Setting as low as you can is (mostly) a CRT thing but not entirely, when you set it as low as you can on an LCD, chances are you'll avoid color shifting that you might not notice. But I would say it's definitely geared more towards CRT's to avoid geometry distortion and other problems.

Since your LCD's probably don't have a perfect grayscale, I'd say to also look at the top 4 or 5 steps in the grayscale steps patterns and try to get those to be as smooth as possible from one to the next.

In other words, get the last box white, the next one slightly gray, the next a little more gray and so on. If you can get those few top boxes slightly grayer with each step, then your contrast will be pretty good (if there is also no clipping or color shifting). You just don't want for instance, a white box, then a darker gray box second, then third a slightly brighter box (I would say that's due to a form of color shifting [not certain though]).

To give you a rough idea, I have an i1Display LT colorimeter (which I highly recommend), and my contrast clips into white at about 75% max contrast, to set it properly, I had to dial my contrast to 52% max contrast!

And like Sperron said, the color shifting we're talking about is VERY slight, it could take a bit of looking to see it. But I do agree that sitting a little further back when looking for it could help!

Hope this makes sense and helps you,

-Brian

Greetings

The white shirt test pattern is better than the DVE step pattern for setting contrast. There are more gradations in the white shirt pattern.

1. No clipping. Maximize visible detail in the guy's shirt.
2. No discoloration. Make sure the shirt does not look pink.
3. Eye fatigue factors. If it hurts your eyes to watch ... turn the contrast down more.

Don't know which "pros" here would be saying to keep the contrast low as possible. They'd better not be ISF or THX since that is not what was taught. Then exactly what kind of "pro's " are we talking about then.

Regards

Greetings

The white shirt test pattern is better than the DVE step pattern for setting contrast. There are more gradations in the white shirt pattern.

1. No clipping. Maximize visible detail in the guy's shirt.
2. No discoloration. Make sure the shirt does not look pink.
3. Eye fatigue factors. If it hurts your eyes to watch ... turn the contrast down more.

Don't know which "pros" here would be saying to keep the contrast low as possible. They'd better not be ISF or THX since that is not what was taught. Then exactly what kind of "pro's " are we talking about then.

Regards


OK, I'll try it that way tonight, and also experiment with kamui's 75% rule of thumb. Thanks.

Actually one of the "as low as possible consistent with a good image" proponents is Guy Kuo (ChrisWiggles) in the Calibration FAQ sticky. It seems that his reasoning is that nobody using the naked eye really knows if they are getting clipping or not (that's just an interpretation on my part). In any event, it is pretty much the opposite of the "keep it as high as you can without failing the test patterns" method that the calibration disc people seem to favor.