HDMI,DVI-D,DVI-I, VGA,RGB,RGBHV… What do they all mean to me? Which should I concentrate on? Is one better than the other? If you have begun working with video lately, the names may have changed but the same principles apply. Now you also may ask the question, What about composite and component? Oh yes, they are still in use. The AV industry just added a few more options.

So let’s look at what these new and not so new cable types are. First, we will look at VGA. This has a 15 pin connector that is often referred to as HD-15 or DB-15. The most common use for this type of cable is to connect your computer to your monitor. This was the first means of connecting computers to projectors. The length of cable you can use is directly affected by the resolution you use. For example, if you are projecting an image at 1024×768@60Hz, the maximum recommended length would be 10 meters or 32 feet. Now, the longer length of cable you use, the more resistance and signal loss you get which translates into noise in your video. I recommend the use of a signal amplifier or distribution amplifier if you plan to mount your projector in the ceiling and use more than 50 feet of cable.

The next type of cable is known as DVI. Often referred by the type of signal it passes, they are called DVI-A, DVI-D or DVI-I. So what does that mean? Well, DVI was the first on the scene. It is now referred to as DVI-Analog. DVI-A cables are used to carry a DVI signal to an analog display(CRT or cheap LCD). In this configuration, DVI-A carries the same signal as a VGA cable. Then there is DVI-D. This is used to directly connect two digital devices, traditionally a video card and digital LCD. DVI-I is the most versatile of the bunch. This type is capable of sending an analog to analog or digital to digital signal. Keep in mind that DVI is not interchangeable. You must use the correct DVI cable to connect your devices.

Ok, we have touched on the most common ways of connecting your computer to a projector, VGA and DVI. Let’s discuss the various ways of getting video signal to your projector or display.

The newest player on the field is HDMI. It is primarily used for HD devices such as HD LCD panels and plasma screens. DVD is the primary device that is connected to these screens and the HDMI cable is capable of sending audio as well so only one cable is needed for both your audio and video signals. The down side is that DVD, HD-DVD, and Blu-Ray are the only devices that have a HDMI port. Computer manufacturer are adding this interface to some laptops but it is still rather sparse.

One lesser known way of getting your computer signal to your projector is known as RGBHV. This is a series of 5 cables that passes the three main colors of video and a horizontal and vertical sync pulse usually terminated in a BNC connector. This type of cable traditionally carries a computer signal to a projector instead of a VGA cable.

A smaller signal such as video does not require the same number of cable connectors as a digital or computer signal does. Therefore, we can enter the world of RGB or component video. This has become a bit more mainstream with the use of DVD players as you found yourself connecting the red, green, and blue cable from your DVD player to your TV that had a component input. It’s still pretty basic but the video signal is divided into three colors so that more information about each can be transmitted to the display device. If you are sending video a long distance or just want a better overall picture, then RGB is the way to do it.

Lastly, there is the composite video signal. This signal can’t be used to transmit a computer signal without a scan converter and only has one small cable. It is the same type of cable used by the TV cable companies. It has every signal transmitted on one cable. Signal quality is ok but should be the last resort used to send video to your projector is you can help it.

Well, I hope this helps you decipher some of the alphabet soup that is video cables. It’s been a while since we have posted but thanks for reading and good luck in all you do. Email us any questions or comments you may have.