Need help with understanding native/max resolution?

[xCUBBYx]

I own a Optoma EP719 DLP Projector. Lately I have been very confused with what the specification XGA (1024 x 768) Native, SXGA+ (1400 x 1050) Maximum means. Basically what begain to confuse me was deciding on whether to use component cables or vga cables with my Xbox on my projector.

Through component cables I have the choice of 720p or 1080i on the Xbox. At the moment I have it set to 720p. I know 720p is a higher res than my native res 1024x768, and I also know know 720p is a widescreen fromat and 1024x768 is 4:3. What I don't understand is what the projector is doing with the extra information when I'm sending it something in 720p.

One person stated to me that the Xbox 360 does not support my projectors native res over component but it will over VGA. He also said that xbox cannot output any res higher than 640x480 with my projector. Know I'm even more confused. What my eyeballs are seeing tells me there is a big visual difference in quality between games (or even just the Xbox menu/dashboard) and normal DVDs. I figured the games are HD and DVDs are not, which is true. If it could only put out 640x480, wouldn't everything have the same quality?

How could my projector be putting out 640x480 when it clearly states that it supports 720p (again, I know 720p is higher than the native res). Why would it be any different between component and VGA? I am very confused. Please Help.

[Oakleyspatz]

Digital projectors are 'fixed pixel displays' and can only display a full screen image at their native res. The fact that they can accept a higher maximum resolution just means that signal is 'scaled' down to fit the PJ's native res.
Your projector is compressing your Xbox image one way and stretching it another way to get a widescreen 720p image to fit your 4:3 XGA screen or your Xbox itself could do this if you select '4:3 TV shape' in the menu. If you looked at your image next to that same image on a 720p widscreen image, yours would look thinner and taller.

Although your PJ is not a true widescreen HD model, its res isn't too far off so a HD signal will definitely look better than a SD signal as there is less scaling to be done.

[xCUBBYx]

Originally Posted by Oakleyspatz

Digital projectors are 'fixed pixel displays' and can only display a full screen image at their native res. The fact that they can accept a higher maximum resolution just means that signal is 'scaled' down to fit the PJ's native res.
Your projector is compressing your Xbox image one way and stretching it another way to get a widescreen 720p image to fit your 4:3 XGA screen or your Xbox itself could do this if you select '4:3 TV shape' in the menu. If you looked at your image next to that same image on a 720p widscreen image, yours would look thinner and taller.

Although your PJ is not a true widescreen HD model, its res isn't too far off so a HD signal will definitely look better than a SD signal as there is less scaling to be done.

So I have two questions, you said the image when in 720p would be thinner and taller when shown through my projector. How off is it? I seem to have always thought everything looks normal, in other words no abnormaly wide faces. Also I created a screen to the exact measurments of 16:9. When watching a movie or playing a game, the image fully fills the screen.

My other question is what would be better, component or VGA. When plugging the Xbox in through VGA I have the option to actually set the res to my native 1024x768. Through component I only have the choice of 420p, 720p, and 1080i. Would it look better if the Xbox was itself set to my native or does it really matter?

[Oakleyspatz]

It would not look too far off the correct ratio unless you did a side by side comparison with a widescreen model then you would notice a slight difference. You may also preserve the correct ratio and have small black bars top and bottom.
I would send it via VGA and maintain the correct resolution of your screen. Basically you have a rectangle image trying to fit onto a square screen so of course it will need a degree of stretching and compressing to fully fit that screen otherwise you'll have black bars top and bottom. But do not let it bother you, if the image looks ok to you then that is all that counts!