Sorry Guys,
i´m still not really "here" due to the lack of sleep i´ve had the last days, so i did not recognized all the replies above.
ok, don´t think i´m crazy and i try to lever the laws of (camera) nature ;)
it´s not easy to describe, i´ll try again.
just besides to mention >>>
# scaling - or moving layer in 3D space = NO
# reducing 720p comp size to DV-PAL Widescreen = NO
heres an example from kindergarten.
1.) use a piece of cardboard an cut out a rectangular hole.
2.) place camera inbetween cardboard and object.
3.) rotate camera.
imagine now the cardboard is the outside area of the composition panel and the object is the layer inside the comp window.
if i rotate the camera and as the camera rotates you would still just see the obscuring comp panel area and the layer would not show the black (or whatever color set) background BECAUSE it is obscured by the (cardboard) outside area.
that´s all what i want to simulate.
if i had a another choice would have shoot it like shwon here at 1:35
-_-