example.cs

// _guiTexture is a texture of a bunch of gui images (buttons, scrollbars panels ect)
// srcRectangle in this case is the source rectange of a 64x64 button

// create render target
// if I set this to the same size of the backbuffer it draws how i expect it, but for some reason 
// changing the width/height of this is changing the look when drawn to the screen...
// this doesn't make sense to me because i'm only using 64x64 pixels of this big area...changing it's size 
// shouldn't have any effect in my mind
Canvas = new RenderTarget2D(Graphics, 800, 600)

_spriteBatch.Begin(SpriteSortMode.Immediate)
Graphics.SetRenderTarget(Canvas)
_spriteBatch.Draw(_guiTexture, new Rectangle(0,0, 64, 64), srcRectangle, Color.White);
Graphics.SetRenderTarget(null)
_spriteBatch.Draw(Canvas, Vector2.Zero, Color.White);
_spriteBatch.End();