VGA to Projector Cabling Question

Discussion in 'Displays' started by Paul::F, Oct 2, 2004.

  1. Paul::F

    Paul::F Extra

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    Hey Folks. This is my first post here. I have a question about cabling...

    I just bought a house that has a SharpVision LCD projector ceiling mounted and a motorized drop down screen already installed in it.

    I have CAT-5 cable running to my component rack and I want to be able to put a laptop in there, connect it to my network with the CAT-5 and show it's images on the projector. Simple plan!

    My question is: how do I connect the Laptop to the projector? The projector has VGA input so that is no problem, but the cable will need to go up the wall (10 feet) then across the attic to the projector (about 15 feet) and then down to the projector (maybe 2 feet).

    I currently have one composite video cable making this trek. I am under the impression that a VGA cable longer than about 15 feet isn't good (I guess because of signal attenuation).

    So I guess my question is: is there a VGA to Component Video converter? Then I could just connect the laptop to my AVR and it would be like any of my other video components? Or does that destroy the quality of the image? Or do I need a long VGA cable with a signal booster or something?

    Anyway, any help you experts could offer would be much appreciated!
     
  2. Chris Moe

    Chris Moe Screenwriter

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    I run a VGA cable around 20 feet and don't really have a problem with signal loss. You can also buy an Extron box that will boost the signal.
     
  3. ChrisWiggles

    ChrisWiggles Producer

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    Converting to component is a bad idea for a few reasons, because in a moment I will describe a better option, and because it is expensive, you'd have to have at least one transcoder in the mix ($$$).

    "VGA" out of your computer, is just full-fledged RGBhv, but in a convenient (inferior) connector and mini cable. You can run a long VGA cable, but it's probably not the best option. Better, would be to use a breakout cable, and then run 5 high quality coax in an RGBhv config to the projector. I do this with my HTPC, but my projector expects RGBhv, it doesn't take the mini hd15 VGA plug, so I only have one breakout cable in the chain (I may eliminate that too, with a BNC RGB out from the computer).
     
  4. Paul::F

    Paul::F Extra

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    Thanks for the replies. Chris can you explain a little more the 5 RGBhv coax setup? I'm not familiar with RGBhv.

    By 'breakout cable' do you mean a converter from the VGA 15 pin connector to 5 RCA plug type cables? R, G, B, and I'm not sure what h, and v are! ??
     
  5. ChrisWiggles

    ChrisWiggles Producer

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    RGBhv is full bandwidth RGB signals with separate horizontal and vertical sync. It is not a compromise like component video is. Your computer outputs this type of signal, for cabling options, this gives you some ideas:

    http://www.bluejeanscable.com/store/rgbhv/index.htm

    For your own reference, I use a breakout adapter, then 30 feet of belden coax to my projector, which takes RGB on 5 BNC connectors.
     
  6. Paul::F

    Paul::F Extra

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    Chris thank you for the link that helps a lot. Now for my next question!

    The very simplest way of doing this for my current setup would be to purchase the 4-ft VGA (15-pin) to 3 RCA connector break-out cable and plumb that into my AVR. Then composite video to the projector. This would feed computer video to the projector in the same way as my VCR/DVD/etc.

    Is composite video adequate or would it kill PQ from the computer? I am happy with the PQ using composite from the DVD so I assume it would be OK but I am not 100% sure.

    Boy those cables are expensive! Plus to run component video to the projector I would have to cut the plugs off the new cable and fish it through my wall face-plate then re-connect the plugs. Since a composite vid cable is already fished up the wall and across the ceiling, I prefer the composite video solution from a logistics POV but there is still PQ to consider.

    Hopefully my question makes some sense to you. Thanks for your help!
     
  7. ChrisWiggles

    ChrisWiggles Producer

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    Paul: you can't do it that way.

    The output from the computer is RGBhv, which takes 5 separate coaxes. You'll need to run all 5 to the projector, as no receiver I know of will switch full RGB. RGB is NOT component video (only 3 cables) and you would need to purchase a transcoder to move between the different formats. You absolutely will NOT want to go all the way down to composite, as you can't support any progressive scan, or any of the high resolutions the computer can output, let alone that I don't even know of a way to go from RGB to composite, so there's also that.
     
  8. ChrisWiggles

    ChrisWiggles Producer

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    Paul: you can't do it that way.

    The output from the computer is RGBhv, which takes 5 separate coaxes. You'll need to run all 5 to the projector, as no receiver I know of will switch full RGB. RGB is NOT component video (only 3 cables) and you would need to purchase a transcoder to move between the different formats. You absolutely will NOT want to go all the way down to composite, as you can't support any progressive scan, or any of the high resolutions the computer can output, let alone that I don't even know of a way to go from RGB to composite, so there's also that.
     
  9. Paul::F

    Paul::F Extra

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    Ah yes. Of course I see what you are talking about now. I understand. And agree.

    Now then - do you fella's here run your wires into the wall using faceplates? (Run them through a faceplate into the wall) If so, am I right in assuming I will have to buy an expensive cable and immediately take wire cutters to it to chop the plugs off? Otherwise how do I get the thing though the bloody faceplate?

    I'm sure there must be a smart way to do this without hacking my cables up, but I'm just not that smart of a guy...
     
  10. ChrisWiggles

    ChrisWiggles Producer

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    I don't use a faceplate with really small holes. I take a regular faceplate and cut a big hole in the middle, and if you're picky about it looking clean, you can have a little wire harness type thing or something like that, i dunno I've never really looked because I'm not that picky where it comes out of the ceiling. Chopping off the terminations is pretty dumb because how will you reterminate? If you bought custom wires already, then I assume you don't have teh capacity to properly terminate that coax (somewhate expensive tools that aren't worth it for small jobs).

    So you make the hole big enough to fit the cable and connectors and everything in it.
     
  11. Allan Jayne

    Allan Jayne Cinematographer

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    If the only cable actually going to your projector is composite, and the projector also has S-video, you are missing a lot of picture quality.

    Using a transcoder to convert component video (Y/Pb/Pr) to VGA (RGBHV) is a good idea if composite is your only alternative. As far as external video processors go , all of the IScan models will take any of your standard definition sources (including the VCR), do the transcoding, and give you VGA.

    Five separate high quality video coaxes can run next to each other non-stop and all be connected to a VGA plug at one or both ends, if that is the only way to connect RGBHV or component video signals. You do need to do intricate soldering, or purchase the cable set custom ready made.

    Video hints:
    http://members.aol.com/ajaynejr/video.htm
     
  12. Paul::F

    Paul::F Extra

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    My projector does have S-Video input. It also has a 15 pin VGA input, Component, composite, and a 9 pin input. It does not appear to support the RGBhv at least as near as I can tell.

    If I want to just use one of these inputs, which is best?
    Component
    Composite
    15-Pin VGA
    9-Pin
    S-Video

    I am using a VCR, DVD Player, Digital Cable Box, and Computer (mainly for graphics not text) that I would like to display.

    Right now composite is the only cable running to the projector (and the only thing my AVR outputs so I would have to upgrade if I wanted a 'single solution' other than composite). I have been very pleased with the quality of the video so far from DVDs.

    I guess my other question is this: if I recall correctly the projector outputs 800x600 max and I'm projecting a 102" diagonal. That seems like fairly low res to me so given that resolution, does the difference between the worst connection and the best connection make that big of a deal?
     

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