The latest HDTVs and video components are capable of delivering a truly spectacular picture. And today's TV makers routinely include a generous array of audio/video inputs even on small, inexpensive models — great news for those of us who remember TVs with just one back-panel input.

But a single wrong connection can seriously compromise video quality. And if you're not that familiar yet with high-definition images, you may not even realize what you're missing. In this article, we'll cover the capabilities and uses of the many types of connections found on today's TVs to help you get the best possible picture from all your video sources.

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.

Using the right connection can make all the difference

The type of video connection you use plays a major role in picture quality, so you'll want to make sure you're using the best available connection between each video source and your TV. Typically, the owner's manual for your video component or TV will have useful tips on the best way to connect different components.

Often, it's not the TV owner who gets the connection wrong though. Cable and satellite TV installers frequently hook up their set-top boxes using the quick-and-easy approach, rather than going for the best-quality picture. We've handled troubleshooting calls from customers who should have been seeing high-definition pictures but actually weren't. So even if your setup was installed by your TV service provider, it's worth checking to make sure the best-quality connection was used. And if you haven't had your cable or satellite TV service installed yet, be sure you have the appropriate cables on hand before the installer arrives, and don't be shy about asking him or her to use them.

The connection types below are listed in order of picture quality going from highest to lowest. Again, you'll want to go with the best-quality connection available. Along with a basic description for each connection, we've noted its maximum resolution, high-def being anything 720p and above; see our article on HDTV resolution for more info.

	HDMI HDMI can carry both video and audio. Sometimes this digital connection can provide a slightly cleaner picture than a component video connection. This is especially true for non-tube-based "digital" TV types such as plasma, LCD, and DLP. The video signal can remain in its pure digital form from wherever it started all the way until it's displayed on your screen. All HDMI connections include HDCP copy protection. HDMI is backwards-compatible with most DVI connections if you use an adapter (video only; DVI doesn't carry audio). For an in-depth look at HDMI, see our HDMI connections article. Signal type: digital Maximum resolution: 1080p
	DVI This connection carries video signals only. On consumer electronics gear, DVI has largely been replaced by the newer, smaller HDMI connection (above). Size aside, the key difference between DVI and HDMI is that on older components, the DVI connection may not use HDCP copy protection, which may make it incompatible with HDMI connections. DVI connections on HDTVs and video components are sometimes listed as "DVI-D" because they can only handle digital signals. Another version of DVI called "DVI-I" is rarer on TVs but fairly common on computers, monitors, and video cards. DVI-I handles both analog and digital signals. Signal type: digital (DVI-D and DVI-I) and analog (DVI-I) Maximum resolution: 1080p
	IEEE 1394 (i.LINK®, FireWire®) Only a handful of TVs today include these jacks. An IEEE 1394 port can carry both video and audio. It's a two-way connection, which means you can use it for recording programs as well as playing them back, for example. Signal type: digital Maximum resolution: 1080p
	Component video The three-jack component video connection splits the video signal into three parts (one brightness and two color signals). This analog connection delivers an extremely accurate picture with clearer color reproduction and less bleeding than S-video or composite video (below). For situations where an HDMI connection isn't possible, component video is an excellent alternative. Signal type: analog Maximum resolution: 1080p (however, many video components will only send video up to 1080i via component video)
	S-video This 4-pin connection usually provides a sharp 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 (below), but don't measure up to component video (above). Signal type: analog Maximum resolution: 480i
	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 (below), but typically not as good as S-video (above). Signal type: analog Maximum resolution: 480i
	Coaxial or 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. 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. If you find yourself tempted to use RF because it's a simple one-cable hookup, and that cable is usually included free in the box, remember that it's the lowest-quality type of video connection. Once the signal has reached your set-top box, use the highest-quality connection from the types listed above. Signal type: analog Maximum resolution: about 350i

To see larger photos of each type of input and connector, visit our A/V connections glossary.

Use high-quality cables for a better picture

Along with choosing the best connection type, high-quality video cables can also improve picture quality. Video signals are actually more vulnerable to degradation than audio signals, due to their much higher frequencies. Interference can cause lines, snow, and other artifacts to appear on your TV screen. A higher-quality cable with good shielding and corrosion-resistant, snug-fitting connectors will ensure maximum signal quality for years of use. For more tips, check out our article on choosing A/V cables.

Connecting A/V gear to your TV

The way you connect your audio/video components to your TV can make your system easier to set up and use. For example, a lot of today's TVs offer front-and side-panel jacks — very handy for hooking up a camcorder, or a video game console that isn't permanently connected to your TV.

Also, you'll need to decide whether to use an A/V receiver to switch between your video sources, or just hook them up directly to your TV. While it's true that adding more cables and components into the signal path can degrade the signal, it's hard to resist the conveniences many modern receivers offer. For example, most mid- to upper-end home theater receivers can convert video signals from one connection type to another. This allows you to run just one cable, such as HDMI, from your receiver to your TV — reducing cable clutter and simplifying setup. For more details on A/V source switching and receivers, see our article on choosing a receiver.

Protect your investment: plug in to clean power

A lot of folks don't think about power protection for their TV — until it's damaged by a power surge. To protect your HDTV investment, you should plug your TV and all of your other components into a good-quality surge suppressor. You can also actually improve your TV's picture, and in some cases extend its life, by using a higher-quality power protection and line conditioning unit. These components clean and filter AC power, often resulting in a noticeably crisper, clearer picture. For more info, see our article on choosing power protection.