A/V settings: What is CVBS and should I use it?

[Deleted User][Deleted User] Posts: 221
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I was checking the TV-Scart setting under AV settings on my 9200T the other day and noticed three options, RGB, S-video and CVBS. The first two I'm familiar with, but what is the third?

I haven't looked at this option since I first bought the Humax 18 months ago, and I don't remember seeing CVBS then.

What is it and should I be using it?

Comments

  • [Deleted User][Deleted User] Posts: 86
    Forum Member
    beachbum wrote: »
    I was checking the TV-Scart setting under AV settings on my 9200T the other day and noticed three options, RGB, S-video and CVBS. The first two I'm familiar with, but what is the third?

    I haven't looked at this option since I first bought the Humax 18 months ago, and I don't remember seeing CVBS then.

    What is it and should I be using it?

    I believe:

    Composite Video, Blanking and Sync

    Key word, composite. So don't use it unless you're forced. Stick to RGB.
  • -GONZO--GONZO- Posts: 9,624
    Forum Member
    Its always been there. Use it if you want ,but its not as good as RGB or S-Video.
    Its the equivalant to using a yellow cable to connect your DVD player to a TV or the standard cable that comes in some video games consoles(well the Wii did anyway).
    On most TVs you will usually find a CVBS input on the front or side of the TV ie Yellow socket for picture next to red and white for audio.
  • DSmanDSman Posts: 1,219
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    I use it instead of RGB because it gives a better (sharper) picture. I know this is contrary to what most people say but for me it's definitely better.
  • [Deleted User][Deleted User] Posts: 2,705
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    DSman wrote: »
    I use it instead of RGB because it gives a better (sharper) picture. I know this is contrary to what most people say but for me it's definitely better.
    Do you have your box connected to the first scart socket on your TV (usually AV1) ? Usually only AV1 is RGB, and if you have any other devices connected in the chain disconnect them because they can normally only pass through composite, or even worse sometimes they convert the RGB signel to composite making it worse than the composite output would be from the box.

    So what im saying is, go back and try it again lol

    -Chris
  • DSmanDSman Posts: 1,219
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    ntlhellworld, yes it's connected to AV1(or EXT1 on mine). There are no other devices involved.
  • tecstartecstar Posts: 509
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    I have my DVD on AV1 set to RGB and my HUmax on AV2 set to CVBS.
  • fixermanfixerman Posts: 1,329
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    DSman wrote: »
    I use it instead of RGB because it gives a better (sharper) picture. I know this is contrary to what most people say but for me it's definitely better.

    I must say that my experience is the same. I have spent a lot of time in the past experimenting with various connections but find the CVBS to be the best. Not perfect but better than RGB.
  • PhilipLPhilipL Posts: 1,118
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    Hi
    I must say that my experience is the same. I have spent a lot of time in the past experimenting with various connections but find the CVBS to be the best. Not perfect but better than RGB.

    What make of TV do you have?

    Regards

    Phil
  • fixermanfixerman Posts: 1,329
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    PhilipL wrote: »
    Hi



    What make of TV do you have?

    Regards

    Phil

    It's a Samsung 32" LCD. Model LE32R7.

    regards,

    Fixerman
  • PhilipLPhilipL Posts: 1,118
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    Hi
    It's a Samsung 32" LCD. Model LE32R7.

    If it was some unheard of brand from Tesco I was going to suggest the RGB input was doing little more than converting RGB to composite, hence difficult to see any improvement.

    RGB is a funny signal, only used in Europe, and was designed to drive the Red, Green and Blue guns of CRT TV's directly and so bypassing all the hundreds of transistors and resistors etc in older style TVs. This gave a big boost in picture quality.

    Trouble is now a days what do you do with RGB on LCD/Plasma TVs? In some cases the RGB in will be converted to S-Video (or composite) than fed into the main chip, especially where the model is sold worldwide and it isn't worth them incorporating RGB input circuitry on the standard design so they just add a small daughter board converter for the European models, for example on the board that houses our SCART sockets.

    If you have a 3DY/C comb filter, that does a remarkable job of cleaning up composite and it looks little different from RGB, but can have a smearing effect.

    So I don't have any answers really, but on modern LCD/Plasma TV's with all their modern processing, there isn't the big startling difference there perhaps once were with different input methods, especially considering they are progressive display showing interlaced video, which is pretty messing anyway. The huge improvement connection method wise on modern panels is feeding in component with a DVD Player playing a progressive film. Progressive on a progressive panel is a big improvement in picture quality.

    If composite looks better, then use it.

    Regards

    Phil
  • [Deleted User][Deleted User] Posts: 86
    Forum Member
    tecstar wrote: »
    I have my DVD on AV1 set to RGB and my HUmax on AV2 set to CVBS.

    Is there a particular reason you don't have the Humax connected to AV1 (outputting RGB) with the DVD player connected to the Humax's VCR scart input (passing through your DVD player's RGB signal)?
  • tecstartecstar Posts: 509
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    Klopek wrote: »
    Is there a particular reason you don't have the Humax connected to AV1 (outputting RGB) with the DVD player connected to the Humax's VCR scart input (passing through your DVD player's RGB signal)?

    No, not really, i've just always had my DVD on its own on AV1.
    I suppose I just hadn't thought about passing it through. Ir RGB will give me a better picture then i might give it a try.
  • fixermanfixerman Posts: 1,329
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    PhilipL wrote: »
    Hi



    If it was some unheard of brand from Tesco I was going to suggest the RGB input was doing little more than converting RGB to composite, hence difficult to see any improvement.

    RGB is a funny signal, only used in Europe, and was designed to drive the Red, Green and Blue guns of CRT TV's directly and so bypassing all the hundreds of transistors and resistors etc in older style TVs. This gave a big boost in picture quality.

    Trouble is now a days what do you do with RGB on LCD/Plasma TVs? In some cases the RGB in will be converted to S-Video (or composite) than fed into the main chip, especially where the model is sold worldwide and it isn't worth them incorporating RGB input circuitry on the standard design so they just add a small daughter board converter for the European models, for example on the board that houses our SCART sockets.

    If you have a 3DY/C comb filter, that does a remarkable job of cleaning up composite and it looks little different from RGB, but can have a smearing effect.

    So I don't have any answers really, but on modern LCD/Plasma TV's with all their modern processing, there isn't the big startling difference there perhaps once were with different input methods, especially considering they are progressive display showing interlaced video, which is pretty messing anyway. The huge improvement connection method wise on modern panels is feeding in component with a DVD Player playing a progressive film. Progressive on a progressive panel is a big improvement in picture quality.

    If composite looks better, then use it.

    Regards

    Phil


    Thanks Phil. I have my DVD player connected to the HDMI input and it is stunning.
  • [Deleted User][Deleted User] Posts: 221
    Forum Member
    Thanks for all your answers, guys. I must admit I too have found that the CVBS seems to give a marginally sharper picture.

    My Humax is connected to the AV1 input of a Sony 32 inch CRT.
  • [Deleted User][Deleted User] Posts: 53
    Forum Member
    beachbum wrote: »
    Thanks for all your answers, guys. I must admit I too have found that the CVBS seems to give a marginally sharper picture.

    My Humax is connected to the AV1 input of a Sony 32 inch CRT.

    I reckon that CVBS is more prone to an electronic phenomenon known as "ringing". What happens is that when there is a change in the picture (eg, the edge of an object) the signal "bounces" and oscillates slightly before dying away rapidly. The overall effect is to produce a black line around objects seemingly making them look sharper - but it is an illusion.

    The same effect is evident when you adjust the sharpness control on you TV set. The sharpness control introduces this "ringing" artificially.

    IMHO these effects, both wanted and unwanted, degrade the true picture. Whenever I get a TV set I go straight to RGB (or S-video which is similar), and turn the sharpness down to the lowest possible value.

    BA
  • [Deleted User][Deleted User] Posts: 430
    Forum Member
    beachbum wrote: »
    I was checking the TV-Scart setting under AV settings on my 9200T the other day and noticed three options, RGB, S-video and CVBS. The first two I'm familiar with, but what is the third?

    I haven't looked at this option since I first bought the Humax 18 months ago, and I don't remember seeing CVBS then.

    What is it and should I be using it?

    http://en.wikipedia.org/wiki/Cvbs
  • [Deleted User][Deleted User] Posts: 8
    Forum Member
    The picture on my CRT television certainly appears brighter with CVBS than with RGB. But I go along with the comment about "ringing", because the quality of the CVBS picture is cruder than I get with RGB.

    Change of topic:
    I've got a Humax Freesat+ box, connected to the AV1 socket of my Sony CRT TV by a SCART lead. So, no HD.

    However, when I switch from any SD channel to BBC HD, there is a ten second delay - and then the picture becomes brighter and sharper. Checking Humax settings after this happens, I find the RGB setting is greyed out. Any idea what causes this, please?

    It only happens with BBC HD. Nothing changes when I try Luxe HD.

    Changing back to an SD channel, the extra brightness & sharpness immediately "switch off" - and the RGB setting returns to black.
  • nvingonvingo Posts: 8,619
    Forum Member
    1964blakda wrote: »
    Change of topic:
    I've got a Humax Freesat+...
    However, when I switch from any SD channel to BBC HD, there is a ten second delay - and then the picture becomes brighter and sharper. Checking Humax settings after this happens, I find the RGB setting is greyed out. Any idea what causes this, please?

    It only happens with BBC HD. Nothing changes when I try Luxe HD.
    Copy protection.
    BBC currently have copy protection turned on for all HD content. They should in course be turning it on and off on a per-programme basis. It inhibits output via RGB and where available component signals.
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