Why do some widescreen DVDs take up more screen space -- from top to bottom, that is -- on 4:3 televisions than others? I have some widescreen DVDs that present massive black areas on top and bottom of the main image and others which fill that area and present very small black areas and more picture overall top and bottom on my 27" screen....are these DVDs with less black areas considered the "matted" format, or am I wrong? Is it just a framing difference on each picture?

Of course, on a 27" screen, I prefer when the films exibit much less black area to top and bottom....