vader / obi fight (ANH) (new scene?)

I was watching the featurette of BIRTH OF THE LIGHTSABER, you see a shot of Darth Vader cutting Obi wan in half, except in this little sequence he actually cuts him in half , letting his cloak fall and the top half still staying there?

Maybe this has already been discovered so please close/ignore this post, still ive done a 2 picture comparison

Scene from Featurette:

http://homepages.tesco.net/michaelgjones/vaderobi1.jpg

original (dvd) scene:

http://homepages.tesco.net/michaelgjones/vaderobi2.jpg

I think the featurette one looks better (not quality wise, as not been tidied up - just special effects wise)

 

I think you'll find the top one is of an earlier concept that they tried to do when filming where Alec/Obi was replaced by a dummy of sorts that was suppose to fall down when chopped in half. However it didn't work so George later decided to do it as an optical effect in post production.

 

that part from the featurette looks very weird


but yeah, it changed from cutting an empty (?) robe, to cutting through thin air while the empty robe falls down.