How to fit 480p(widescreen) for Xbox (using XNA)?

Question

I read about the Xbox 360 Programming Considerations on MSDN and it shows that both 480p(widescreen) and 480p(normal) uses 640x480. My game works fine on all 16:9 resolutions and it also works on other resolutions, but the game looks very different (because it's in 2D). I tested it on 720p and 1080p and I found that if I set the resolution to 1080p it still works on 720p TVs, and everything looks exactly the same as 1080p (I think Xbox automatically resize the entire game to fit 720p).

But I want to know what other aspect ratios that Xbox supports. Also I'm wondering how to fix the resolution to make it fit on 480p(widescreen)

EDIT: I'm currently using the code below (since my game is designed for 1080p)

    float ratio = graphics.GraphicsDevice.DisplayMode.AspectRatio;
    if (ratio == (float)16 / (float)9)
    {
        graphics.PreferredBackBufferWidth = 1920;
        graphics.PreferredBackBufferHeight = 1080;
    }
    else if (ratio == (float)4 / (float)3)
    {
        graphics.PreferredBackBufferHeight = 1080;
        graphics.PreferredBackBufferWidth = 1440;
    }
    else
    {
        graphics.PreferredBackBufferHeight = 1080;
        graphics.PreferredBackBufferWidth = (int)(1080 * ratio);
    }

Answer 1

"The Xbox 360 system supports both HDTV and normal television sets, at multiple resolutions (480p, 720p, 1080i, and 1080p), and multiple aspect ratios (4:3, 16:9, and 16:10). The console automatically scales the output of a game to the resolution of the owner's display, and if the game is using a widescreen aspect ratio, the console automatically adds "black bars" (letterboxing) if the owner's display is not widescreen."

Source: http://msdn.microsoft.com/en-us/library/bb203938.aspx

Answer 2

If the game resolution is down from the XBox360, go to the settings on the Xbox,and find the screen size and fit it to your TV. If this doesn't work and you don't see a better improvement try adjusting your TV to better perform by using contrast/brightness/sharpness/colors. If this still doesn't improve the way the game looks then its probably the games mapping. If the maps were set higher, it would look better, but would slow down the rendering from the system degrading its integrity over time, until you experience a critical shut-down or the "ring-of-death". So sometimes the textures will look imperfect, or the bump maps will look bad, it's because the console can only handle so many variables and renderings at a time. Refer to Fallout3, look at the textures, from a distance it will look nice, but up close you will find it difficult to read posters, products, nuka-cola's, bottle caps, etc. I have found a huge list of things I believe could be better, but I am more satisfied when the game just works rather than super-perfections.

This might be off the topic a-bit, but I thought I should get involved in something today.

Sincerely: Joel D. V. c2002-2013