For each video source, use the best-quality connection available. For all high-definition sources, be sure to use an HD-capable connection: component video, DVI, or HDMI.

Make sure you make the right connection

Another way to ensure that you're getting the best possible picture is to make sure you're using the best available connection between each video source and your TV.

• HDMI: This digital connection can carry high-definition video up to 1080p, as well as multichannel audio. It should be your first choice when connecting a high-def video component to your TV, though component video is an excellent alternative.
• Component video: This three-jack analog connection splits the video signal into three parts (one brightness and two color signals). Component video is capable of high-def video, and delivers an extremely accurate picture with clearer color reproduction and less bleeding than S-video or composite video.
• S-video: This 4-pin connector usually provides a sharp, high-resolution picture by transmitting the chrominance (color) and luminance (brightness) portions of a video signal separately. The signals can then be processed separately, reducing interference. S-video connections generally outperform composite connections, but don't measure up to component video since they aren't capable of high-def.
• Composite video: This is the most universal video connector, found on most TVs made in the last 20 years. Picture quality is a big step up from RF, but typically not as good as S-video.
• RF: Probably the most common way folks shortchange their TV's picture quality is through the overuse of RF-type connections. There's a reason the RF inputs on TVs are usually labeled "Antenna" or "Cable" — those are the signals they were designed for. Even though it's a simple one-cable hookup, and that cable is usually included free in the box, it's the lowest-quality type of video connection. RF-type connections should generally be limited to bringing signals into your A/V system from outside your house: TV antenna, cable TV jack, or satellite dish. Once the signal has reached your set-top box, use the highest-quality connection from the types listed above.

In addition to choosing the best connection type, using a high-quality video cable can also improve picture quality. Video signals are actually more susceptible to degradation than audio signals, due to their much higher frequencies. And, as with audio, radio frequency and electromagnetic interference can taint the signal. This can cause lines, snow, and other artifacts to appear on your TV screen. A higher-quality cable with a copper conductor, 75-ohm impedance, good shielding, and corrosion-resistant snug-fitting connectors will ensure maximum signal quality for years of use. See our article on choosing cables for more info.

Some picture quality "problems" can't be fixed, only improved

High-definition TVs can do things conventional TVs could never dream of. But here's an important point to keep in mind: Even the finest HDTV can't magically repair a mediocre video signal. Some owners of new HDTVs have been disappointed to find that their favorite regular TV shows don't look much if any better. That's the fault of the signal, not the TV. Those shows are being broadcast at the same quality they were before. Your new TV may have some processing you can turn on to improve picture quality a little. But ultimately, the picture you see is only as good as the signal your local station, cable company, or satellite company is sending you. Old-fashioned tube TVs are very forgiving of low-quality signals.

A lot of the recommendations we've made in this article can help when it comes to mediocre signals, but for more tips, check out our article on improving the look of non-HD sources on your HDTV.

And finally, no article on picture adjustment would be complete without mentioning aspect ratio (picture shape). How many times have you sat in a restaurant or bar watching a TV with the aspect ratio set incorrectly and wishing somebody would fix it? The telltale signs are people onscreen that look either too short and stocky or unnaturally tall and thin. Conventional TVs and programs have what's called a 4:3 ratio, while HDTVs use the widescreen 16:9 ratio.

We're still in the transition period from analog TV broadcasting to digital, so most of us will be watching a mix of regular and widescreen programs. Try to get familiar with the different aspect ratio modes your TV offers. Usually, there's a dedicated button on the remote, often labeled "Wide," that lets you cycle through several options. Often, some combination of zooming and stretching will yield a picture that better fits the wider screens found on HDTVs. Check out our article on aspect ratio for more info, as well as tips on troubleshooting aspect ratio problems.