How to Use the HDNet Test Pattern to do Basic Calibratio
12-14-2008 11:54:35 AM
This is a brief introduction to how to use the HDNet test pattern to to two basic calibration adjustments to your TV.
Record the HDNet Test Pattern
The first thing you need to do is record the HDNet test pattern if you haven't done so already. The test pattern airs once a week on HDNet (channel 1105), at 7:30AM ET/4:30 AM PT Saturday mornings. It is 10 minutes long, and is labeled "Off Air" in the program guide.
The HDNet test pattern runs 10 minutes, and actually consists of 3 different patterns. The first includes color bars and a brightness scale at the bottom, this is the most important pattern. The second is a convergence pattern, which is pretty useless for most of us, as it only applies to rear-projection CRT TVs. The last one is a sharpness pattern, which we'll use briefly to adjust the sharpness.
Component or HDMI
I have tried to perform adjusments with U-Verse on both HDMI and component settings, and I have successfully calibrated on both, but HDMI has a twist to it. See my next post in this thread for the details regarding HDMI. To summarize, there are some TVs where an extra setting will be required to get a proper calibration on HDMI, and there are some TVs where getting a proper adjustment on HDMI will be impossible. For the easiest calibration, I recommend you use the Component (Y-Pb-Pr) connection.
There are some settings on your TV that we need to set first. On most of today's TVs, these settings are independently retained by the TV for each different input. You must do the adjustments with your TV selected to the U-Verse input. This shouldn't be a problem when using the recorded HDNet test pattern, as you'll have to have the U-Verse input selected to see the recording. But I mention this because it would not work properly to switch your TV to a DVD input, adjust it using a DVD with test patterns, and then switch back to the U-Verse input.
Also, most TVs nowdays have several "preset" modes available that are variously labeled, such as "Movie", "Cinema", "Standard", "Normal", "Sports", "Vivid", etc. Most of the time, you need to set this to "User" or "Custom" in order to be able to change the base settings. Start with the "Standard" or "Normal" settings, and then switch to "User"/"Custom" to be able to change everything else.
Color Temperature: A few TVs do not have this setting, but if yours does, I recommend setting this to "Neutral" or "Medium". This is somewhat a matter of personal preference. "Warm" settings tend towards the color balance used in movies, whereas "Cool" tends towards the color balance used for sports.
Automatic Brigtness: Some TVs have an automatic or dynamic brightness setting, variously labeled "Auto Brightness", "Dynamic Brightness", "Energy Saver", "Advanced IRIS", etc. This needs to be turned off.
Noise Reduction: Some TVs have settings for noise reduction or MPEG artifact reduction. I recommend you start with these settings turned off, and later turn them on at a low setting to see how they look. With the proper adjustment we're about to do, you may find that you don't need this.
Other Settings: If you have any other advanced settings on your TV such as White Balance, Color Space, Black Correction, Gamma, etc, set these to their default settings, or "Off" if it's an On/Off feature.
Brightness and Contrast
These are the two most important adjustments and the ones we'll be adjusting using the HDNet test pattern.
To adjust brightness (may be labeled "black level" on your TV), bring up the brightness adjustment control in your TV menu while viewing the HDNet test pattern 1 (the color bars). At the bottom of the test pattern is a brightness scale consisting of 11 squares that proceed from a bright white square with a "0" in it (the "0" may not be visible) through gray squares, finally ending in a black square with a "10" in it (the "10" may not be visible).
Turn your brightness control up/down until the "10" in the black square is just barely visible in a dark room. The "10" should be such that if you were to turn the brightness level down one more notch, the "10" would disappear.
To adjust contrast (may be labeled "picture" or "white level" on your TV), bring up the contrast control in your TV menu while viewing the same HDNet test pattern 1 (the color bars) that you used in the brightness step.
This one is a little more difficult to adjust because the U-Verse outputs seem to be slightly out of spec, and have whites that are a bit too high. Theoretically, what should be done here is to raise/lower the contrast setting until the "0" in the leftmost white square is just barely visible. However, you may not be able to get the "0" to be visible under any setting of contrast on your TV. In this case, turn your contrast up to brighten your whites, but stop turning up the contrast when any of the following occurs:
- The "1" in the second square begins to disappear.
- The first white square "blooms" or begins to get larger than the other squares.
- The first white square begins to change color from white. DLP TVs in particular will start to color this square pinkish when the contrast gets too high.
- Your TV geometry begins to get non-linear, such as when the vertical white bar on the left side of the screen begins to "bow" or show that the line between it and the yellow bar deviates from a straight line.
- You cannot see a difference in the white between the first and second squares. (The second square should actually be a very light gray, not pure white).
At this point, the contrast is now correctly set.
Because the contrast adjustment can affect the brightness adjustment on many TVs, recheck the brightness setting using the black box with the "10" in it. You may need to go back and readjust both the brightness and contrast a few times before you find the right balance.
Unfortunately, it is not possible to do proper color adjustments with the HDNet test pattern, because the proper color bars are not next to each other (white has to be next to blue, and magenta has to be next to cyan). If you want to adjust the color and tint, you need to purchase one of the calibration DVDs I talk about below.
Fast forward the HDNet test pattern to the 3rd pattern (the sharpness pattern).
Sharpness is an adjustment on TVs that emphasizes edges of objects. Unfortunately, this also blurs fine detail. It is advantageous to actually turn your sharpness down or off to avoid this problem.
In the sharpness pattern, you will see many fine black lines on a gray background on the set in various places in the pattern. If the sharpness is set too high, there will be white bands that appear in between the black lines, obscuring the gray background. Turn the sharpness down until the white bands go away and the gray background is visible betwen all black lines. This enables your TV to reveal fine detail that is otherwise obscured by the sharpness control.
This is applicable only to people who have rear-projection CRT TVs. The second HDNet test pattern is a series of white crosses on a black background. If you have a rear-projection CRT TV, bring up the convergence adjustment (see your TV manual) and adjust the red/green/blue convergence until all the crosses are pure white, with no red or blue fringe visible at the edges of each cross. This is hard to do, because each time you adjust the convergence for a certain part of the screen, this tends to alter the convergence in another part of the screen. You may want to have a professional ISF calibration done by a certified technician if you have a rear-projection CRT TV, as they are notoriously hard to adjust.
At this point, you have a fairly well-adjusted TV for U-Verse. You may notice the amount of MPEG compression and noise that is visible now, as the factory-setting modes tend to hide that fine detail. If this is the case and you have a "Noise Reduction" or "MPEG Artifact Reduction" setting, you may try turning it on now. Unfortunately, these settings blur fine detail, defeating the purpose of the adjustment you just did, but you may want to see what they look like nevertheless.
Options for More Advanced Adjustment
If you'd like to perform more advanced adjustments for your TV, there are several options.
The least expensive is to use one of the calibration DVDs, such as:
These calibration DVDs have step-by-step instructions for all adjustments, including color and tint adjustments using the included color filters. They also typically have an audio setup section so that you can verify your surround sound setup. Be aware that if you use one of these to calibrate your TV for U-Verse, you will need to temporarily plug your DVD or Blu-Ray player into the same input you're using for U-Verse so that you're adjusting the correct input.
A more expensive option, but one that will give you near ISF-quality calibration is the SpyderTV. This is a hardware colorimeter that uses a laptop and specialized software to adjust the TV. I have one, it works very well.
Just a word on cables: I of course recommend you use good cables, as bad ones will cause problems. But component and HDMI cables do NOT have to be expensive. Monoprice.com offers a premium set of component cables for only $10.28, and HDMI 1.3a/Category 2 cables for $4.74.
Remember: Friends don't let friends buy Monster.
Edit 12/14/2008: Changed "Component or HDMI" section to reflect new information regarding HDMI calibration.
Edit 12/15/2008: Fixed some wording related to HDMI and component connections throughout. Update Monoprice.com cable links and pricing.