Sharp Aquos View modes and playing movies!?

Can someone describe each view mode on a Sharp AQUOS TV?

There are stretch, dot-by-dot, smart stretch, and zoom. Looks like dot-by-dot retains the original image down to each pixel, but I don't understand what the others do. When I have HD content on dot-by-dot, it leaves empty space to every side of the screen. If I stretch or zoom, it fills up the whole screen, but is it good?

My most important goals are to preserve aspect ratio, and see the whole picture (not cut any of it off). I don't know which view mode makes it so that if the original image doesn't happen to be exactly 16:9, the TV displays it with at least one end touching the edge of the screen.

My second issue: movies in 1920x800 (2.40:1) file resolution don't play back at that same resolution on the TV; they still play at the 16:9 ratio. I can't tell if the sides are getting cut off or it's being stretched. Any help here too?

any help please?