Video Signals & Cables: Composite Video

In this article, we look at composite video signal: what it is, what cables to use, where composite video is used and the problems with it. This is the first in a series of articles outlining the different video signals used in home entertainment for connecting VCRs, DVDs, set top boxes, cameras and laptops to TVs and projectors.

What is Composite Video?

As the name suggests, composite video is “composed” of everything required to make up a TV picture. It has the basic black & white picture information (luminance or luma), along with the colour information (chrominance or chroma) as well as the timing information (sync). It is the most basic (and simplest) form of video signal.

Cables to use for Composite Video

You are probably aware of the yellow, red and white connecting leads. The yellow one is generally used for composite video (the red and white ones are used for left and right sound). The plugs on each end are called RCA plugs, and these leads are normally called RCA leads, or AV leads (audio and video). These leads are good for short distances up to 5 metres (15 feet). For longer distances (to connect to a projector), thicker cable should be used for composite video signals. This larger cable is normally called RG59. It can be used for distances up to 100 metres. You can buy pre-made RG59 video cables in 5, 10, 15 and 20 metre lengths. For longer lengths, the cable is normally installed and then the connectors attached (soldered or crimped).

If you need to purchase a cable, here is a link to Amazon’s range of RCA Cables

RCA comes from the company Radio Corporation of America. RCA originally used these plugs to connect phonographs (record player) to  radio/amplifiers. Hence RCA plugs are also known as phono plugs.

Where Composite Video is used

Composite Video is used mostly for Standard Definition TV, and not for High Definition. Composite Video was used extensively in Video Cassette Recorders (VCRs) to connect to TVs.  The familiar yellow RCA lead is simply connected from the yellow “Video Out” socket on the VCR to the yellow “Video In” at the back of the TV. Generally the red and white audio leads are connected to their respective coloured sockets for the audio.  Longer video cables are also connected between a VCR and a projector.

As Composite Video is a basic video signal that all TVs and projectors can use, the familiar yellow “Video Out” socket is still available on DVD players and Set Top Boxes so that older TVs can still be connected to them.

Problems with Composite Video

A TV or projector needs to separate the various bits of picture information (luma, chroma and sync) in order to re-create the picture, and this is the problem with composite video. It is impossible to separate all the information back to the original quality once it has been mixed together in the one cable. This means the picture is not as crisp and the colours not as defined as they could be.

For a better understanding see the companion articles on S-video, RGB videocomponent video and HDMI.

10 COMMENTS

  1. I have a Proscan flat screen TV and a duel VCR/DVD player to hook up. I have tried red, yellow, white cables on each end with no success. I tried red, yellow, white on DVDs end and Hamilton connector on tv end. No success. Can you help me.

    • Hi Jeff,
      To watch both Videos and DVDs on the TV you need to use a yellow, red and white cable. On the back of the VCR/DVD it is the 2nd vertical row of connections from the right, labeled DVD/VCR. The other end connects to the TV, but the yellow cable connects to the green socket, and the red and white audio leads connect to the adjacent white and red sockets (as shown on page 12 of the TV manual).

      To just watch DVDs in much better quality, you can use green, red and blue leads for the video, and red and white for the audio (same as above for the audio). The green, red and blue from the DVD player go the same colors on the back of the TV (as shown on page 11 of the TV manual).

      hope this helps

      Geoff

  2. I want to connect my laptop to my older big screen tv. My problem is, my older tv only has the composite connection ports and the S-Video port. I have three usb ports on my laptop. Is there a way to connect the two of them.

    • Hi Richard,
      It is possible to connect your laptop to an older TV, but not real cheaply, and not at computer quality. Normally you would want to use the VGA output, as if you are connecting to a 2nd monitor. However you will need to connect this to a convertor (like this) which converts the VGA signal to a composite video signal.

      These boxes will take the computer image, and convert it to standard definition TV, so in your case the resolution will be only 640 x 480, a lot less than your computer monitor resolutions. There are cheaper units, but I find they often only work with a small range of computer resolutions. A lot of the convertors also output S-video which you can also use.

      I have used this method many times when a computer image needs to be displayed on an older TV.

      hope this helps,

      Geoff

  3. Im not sure if this is the proper forum. but I cannot seem to find an answer. I have an rca cable made up of red, green, and yellow colored connectors. I do not know what the intended use of this cable is, and cannot find an answer on the internet. Thank you………..Emilio

    • Hi Emilio,
      It certainly is an unusual color combination. However the colors don’t really matter. There are traditional or standardized colors mostly used, but the colors are there simply to help you identify which lead you have going where. It is the connectors that really matter. Normally the yellow would be used for composite video, and the red and black (or green in your case) would be used for left and right audio. Really you can use them any where you need RCA connectors at both ends.

      Alternatively, it was a four or five way (like a RGB + audio) cable, and previously someone has stripped off the blue and white to be used else where.

      Sorry I can’t help any more.

      Geoff

  4. Hi Geoff,
    Thanks for all your information, my question: i have a amplifier with ports for CD and DVD inputs, that is for left and right (2 inputs), if i connect my TV with the video cables red and white in the audio ports, will this work from my DVD port from my amp?

    Thanks
    Alfred

    • Hi Alfred,
      I’m not exactly clear what you are trying to do. If you want to connect the audio out from the TV (red and white) to the audio in (DVD) on your amp, then yes the audio from the TV should come through your amplifier speakers when you select DVD on the amplifier.
      Hope this helps
      Geoff

  5. Hi there…
    Thanks for providing some very informative information.  A question for you…I have a Majestic 12 volt television in a motorhome. The picture works fine on normal television reception (off the aerial input) but when selecting the video input (DVD) which uses the yellow/red/white [RWY] cables, all I get is a faint gray picture. I have tried powering off/on at the the power source, uplugging and reconnecting the RWY cables and played with the picture settings – all to no avail. Any ideas please?

    • Hi Dave,

      I would like a bit more info for a better diagnoses. Are you connecting the yellow video out from the DVD player to the yellow video in of the TV? or are you connected to the the Green “Y” outlet of the DVD player?  

      Geoff

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