Projector Resolution help

Your projector has 1024 by 768 pixel native resolution and is essentially a 720p projector. However, this projector has a native 3 x 4 aspect instead of the 16 x 9 ratio that is used for HDTV, therefore when displaying HD video there will be black bars at the top and bottom of the image and the displayed HDTV image will only be about 1024 x 575 pixels, which is not true HDTV resolution, but better than standard definition. With a PC you can use the VGA connection with the PC set to match the projector's the native 1024 x 768 resolution and this will provide best results. Do not confuse a component video connection on a projector (which on your projector supports the HD input signal formats of 720p and 1080i, but not 1080p) with the composite video input which is strictly for standard definition signals and uses a single connector that is usually yellow in color. The single yellow video plus red and white audio connectors on your projector are thus for standard definition only. Also the S-Video connector on the projector is strictly for standard definition. When using a HDTV source with your projector you will need to connect it using a component video connection. However your specific model of projector uses the 15-pin connector for both VGA (for PC connection) and for also for component video from the HD video connection. In order to use it as a component video connection you will need a special cable. See page 22 of the owner's manual for info on the connection and page 25 describing the menu for selecting the video input. You may be able to use the following VGA-to-RCA video cable plus a triple Female/Female RCA adapter to, in effect, provide the projector with a standard component video input configuration (with one connector for Y, one for Pb and one for Pr signals and these are usually color coded green, blue and red with component video cables). You would then use a standard component video cable (with 3 connectors or 5 connectors if stereo audio is included) from the HD video source to the projector (actually from the HD source device to the component video adapter cable you have made up as described above. Below are links for where you can purchase the cables and adapters.

VGA to Component Video (RCA) adapter cable -

HERE
F/F RCA coupler (a triple version for component video) - HERE Standard component video cables:

6 ft. video only (no audio) -

HERE
6 ft. video and audio - HERE

www.monoprice.com has many other component video cables in other lenghts and also higher quality cables. Most Blu-ray players up until fairly recently had such component video connectors (but some new models do not) and you will typically also find component video connections on Directv, Dish Network and Cable TV HD set top boxes and HD-DVRs. You will probably need to go into the settings menu on the Blu-ray player, sat. box or cable box or other HD video source device and set its output resolution to 720p.

Ron answered well but I will add a couple things:

Input resolution and native are not the same. No matter what you feed a projector or what it says it can take, a digital projector always converts to the native panel. So really 1024x768 would be the output.

Secondly, only component, VGA and HDMI can take a signal higher than 480i. Anything you feed composite or s-video will always be 480i.

Hope that helps.

1080i should look as good as 1080p as long as the video is deinterlaced properly.

The 720p and 1080i are HD signals formats that your projector can accept at via its component video input, but in all cases the projector will digitally process the input signal to match the projector's native 1024 x 768 pixel resolution. Your projector owner's manual spec. page does not list 1080p as a signal format it can accept so it will not be expected to produce a usable display if you attempt to input that signal format. In any case, setting the source HD device (e.g., Blu-ray Disc player or Directv HD receiver) to output in 720p mode will probably give you the best results. As for 16:9 (or 1.78:1) vs. 4:3 (or 1.33:1), your projector's display chip is actually 4:3 and when used in 16:9 mode it simply inserts black bars, or unused space, across the top and bottom of the image to create an central area with a wide screen 16:9 (1.78:1) aspect ratio image (as used for HDTV). This essentially means that the resulting vertical resolution that is available to display the actual 16:9 image is about 575 pixels with the remainder of the projector's available 768 vertical pixels being used to display the black bars. In either case the horizonal resolution is fixed at 1024 pixels. Specifially 1024/1.78 = 575. This is the hardware limitation of your projector and there is nothing you can do about it.

The PC should be set to output 1024 X 768 resolution since that is the native resolution of the projector (and the highest resolution it can possibly display).

Again, that is the native of the projector. No matter what you feed it, that is what it will display. Ideally for a PC, you would want to set it to 1024x768 on that projector. As Ron said 720p and 1080i and signal formats...outputs from a source. But your projector will take that and convert it to 1024x768. Why projectors often list a bunch of different resolutions is to let the person know they are compatible. For instance, your unit will not take 1080p, so if you fed a source of that resolution to it, you would not get any picture.