Tune Up Your Television
July 13, 2002,
I went to the gym the other night and there he was—Larry King's overcooked reddish-orange face glowing from one of the TV sets above the treadmills. On another set, there he was again, but this time he was kind of sickly green looking. On yet a third TV the poor guy had a purplish cast to him. No excuse for this, I thought. Something has to be done.
Folks, lousy video is rampant in our society. It's time we put a stop to it! Bad enough we get it at the gym, but the sad fact is most of us settle for mediocre to poor video on the TVs and projectors in our very own homes.
Now as blights on society go, bad video is admittedly not one of the biggies. But it's something we can do something about. For the vast majority of projectors and TVs in use today would look a LOT better with just a few tweaks of the picture control settings.
Problem is…most people don't know how to fuss with the brightness or contrast or sharpness controls to get them set right. Why? Simple: manufacturers NEVER bother to tell you how to do it, and the guys at your local TV retailer don't know how to do it. Invariably owner's manuals just tell you to adjust them until the picture looks good. And frankly, that is an absurd way to go about optimizing a video system.
SO! In order to liberate the world from the scourge of horrendous video, we offer up these simple instructions on how to get your projectors and TVs tuned up to deliver much better pictures that you are getting from them today.
Here's what you need: (1) a DVD player and (2) your favorite movie that has a scene with good solid textured blacks (say, James Bond in a tux), and also a scene with good bright, white, textured highlights (textured white fabric or a whitewashed fence in sunlight would be ideal). If you happen to find a single scene with both black and white elements in it, so much the better! Now you are ready for your video tune-up.
Every video system has five basic adjustments for optimizing the display of an NTSC signal. They are most frequently known as brightness, contrast, color, tint, and sharpness. However, your projector or TV may have different names for them. Tint is often called hue, and sharpness may instead be called detail. On occasion brightness is called picture. (There is no end to the confusion manufacturers foist on the helpless consumer for no reason whatsoever.)
To optimize the picture quality of your projector or television, make the following adjustments to the five basic picture control settings:
BRIGHTNESS. Your owner's manual probably says that the brightness setting is used to control "brightness" or "picture intensity" or something other fuzzy non-descript term. The truth is that brightness is used to set the BLACK level in the picture.
On most TVs and projectors in use today, brightness is set too high. That's because people think "a bright picture is good, so I will set it as bright as I can get." Well, that's nice in theory, but entirely wrong in practice. Setting the brightness level too high makes a black tuxedo look gray rather than black. It muddies up the shadow areas, and reduces the overall snap and crispness that the picture would have if properly calibrated.
To find the right setting for brightness, go to the image in your movie that has textured blacks and hopefully some shadow/low light areas in which there is detail. Then freeze on that frame. As you move the brightness control down, the intensity of the blacks will increase, and shadows will get darker. As you move the control all the way to zero, you will (hopefully) see that the low light shadow areas will also go to solid black and lose their detail.
The optimum setting for brightness is achieved at just the point where true black objects appear as black as your system will make them while retaining as much visible detail in the shadow areas. Above this point the blacks appear to go grayer. Below this point you lose detail in the shadows. On many video systems, this optimum point is toward the lower end of the brightness scale. But find the point that looks correct to you regardless of where it is on the scale.
CONTRAST. The contrast control is similarly confusing. It is also often set too high on the theory that contrast is good, and therefore we might as well get the most we can out of our set by turning it all the way up. In fact, the contrast setting is used to control the intensity of the brightest highlights in the picture, so it is (oddly enough) the opposite of brightness control.
First, find your test scene in which you find textured whites in bright light, and freeze that frame. You are looking for the brightest elements in the picture in which you want to retain visible detail.
Let's assume you have a whitewashed fence in sunlight. If you start with the contrast set low, the fence will appear light gray rather than white. As you move the contrast control up, the fence will get whiter. Eventually details in the texture of the fence will begin to disappear.
If you continue to push contrast past the optimum point, the wood-grain texture of the fence will go solid white and all visible detail will be obliterated. Push contrast up even a little further, and our fenceposts might actually appear to expand very slightly due to a glow around the edges. This phenomenon, called "blooming" is a definite sign that your contrast setting is overcooking the image (and maybe your picture tube as well—don't ever leave the contrast control set this high!!!)
Find the point at which whites look white while retaining as much texture detail as possible. This is your optimum contrast setting. On most video systems, this setting is toward the higher end of the scale, but it can be anywhere. Find the point that looks correct to you. (By the way, unlike TV's, digital projectors will not bloom)
Now…note the following: brightness and contrast can be to some degree interactive. Your new contrast setting may have affected your brightness. So return to the brightness scene and verify that your blacks are still black, and you still have maximum detail in the shadows. Adjust it if necessary, then return and adjust the contrast setting once again if necessary. (You can see that this is much easier if the black and white elements you are testing all appear in the same image!)
COLOR. The color control on your set determines the level of color intensity in the image. One of the most common errors people make in calibrating their video systems is overdriving the color. That's what makes Larry King look reddish-orange on the TV at the gym. Overdriving color is common because once again, people naturally think, "I want to get as much color as I can out of this color TV, so I will crank it up some to make sure I get the most out of it!" No. Bad mistake.
If you move the color setting down to zero you will notice that your picture will turn into a black and white image. The optimum setting for color is achieved by increasing the setting just to the point where colors look natural and not a bit more! Flesh tones should look natural and without any hint of an unnatural glow. Grass should look naturally green rather than screaming spray-paint green.
When adjusting color, make sure that your test image has relatively unsaturated colors. Flesh tones or natural landscapes are ideal. It is impossible to set color properly if you are using a brilliant red Ferrari as your test subject.
On the large majority of video systems, the optimum setting for color is somewhere near the middle of the scale. However, trust your eyes for the optimum setting and think "what looks like the most natural, accurate reproduction of reality?" Any overdriving of color will make the image look artificial.
TINT or HUE. The tint control adjusts color balance rather than color intensity. It is an easy control to set properly, but for some reason many people don't get it right. When flesh tones look either too green or too magenta, a phenomenon you see with amazing frequency, it is because the tint control is not set properly.
Find a human face and freeze-frame it. (In choosing your test subject, note that lighter skin tones will show errors in tint more readily than darker skin tones). As you move the tint control to one end of the spectrum, the face turns green; as you move it to the other extreme, the face turns magenta (red+blue).
The correct setting for tint is the point near the middle of the scale at which you can detect no hint of either green or magenta. It is the most neutral point between the two extremes. The flesh tone looks the most natural at this point.
SHARPNESS or DETAIL. The final setting is sharpness or detail. Now, pray tell, who in their right mind wouldn't want the sharpest, most detailed picture they could get? And since there is a control that lets you turn it up, why not turn it up? That's what many folks do, and of course it's exactly the wrong thing to do.
The sharpness control adds processed information to the picture that is NOT part of the original video signal. It adds artificially highlighted edges, and makes the picture look less natural than it otherwise would. This is most evident along the continuous edge of a dark object against a middle-toned background. When sharpness is overdriven the dark edge will be outlined by a white ringing effect that increases contrast just along the edge of your dark object. That edge "highlighting" effect is created by the sharpness control. It is an artificial manipulation of the image. It wasn't in the original scene, and it shouldn't be on your screen either.
On most televisions, the optimum setting for sharpness is zero. On many digital projectors, the optimum setting is either in the low or middle part of the scale. Picture tube televisions and digital projectors behave differently in this regard; on a digital projector it is often possible to fuzz the image by setting sharpness too low.
Now look at your picture with the sharpness turned down or off depending on what works best on your system. You will see a smoother, more natural image. It might take some getting used to, since you may be accustomed to viewing video with all the artificial edge enhancements that create the illusion of added sharpness.
However, when the interference and noise from the artificial sharpness enhancer is removed, you are seeing the most genuine reproduction of the video signal that your projector or TV is capable of. And if you view it for a while, you will gain an appreciation for just how smooth, natural, and satisfying the picture can really look.
For extra help -- The AVIA Guide to Home Theater
If you want to go a step beyond eyeball calibrations, then you need a DVD called the AVIA Guide to Home Theater. It goes through all of this in more detail. And it also gives you all the test patterns you need to set each of the video controls with absolute precision, so you don't need to rely on a black tux and a white fence to approximate your black and white levels.
That's it! Now there's only one thing left to do…
You have just given yourself a free video upgrade. But remember…it's tragic but true…the rest of the world is still mired in a morass of mediocre video. You can help by passing along this article to friends, family, anyone you know who would want better video. And don't forget the manager at your gym.
(note: You can "Send this Page" to someone right now by clicking the link below.)
Now go forth and enjoy your new higher-performance TV or projector, and thanks for visiting ProjectorCentral!
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