the movie balrog

There is nothing to indicate that the Balrogs are on a different scale than very tall humans. Tolkien's decription of them seems to indicate that it is difficult to see what they look like as they radiate shadow. They also radiate terror. The notion that they are 20 feet tall just doesn't work for me. It's the power radiating off of them that is so scary, not their size.

The Elf-lord Ecthelion of the Fountain, however valiant, couldn't have fought a duel with a 20 foot tall demon. Gothmog (the lord of the Balrogs) had many battles with Elven lords. These battles imply foes on more or less the same scale. A creature the size of the Balrog in the LOTR movie wouldn't simply kill an opponent. It would smash it to jelly. Nothing of the sort is described in any of Tolkiens references to the Balrogs. ...

Of The Bridge of Khazad-dûm

...The outer door could only be reached by a slender bridge of stone, without kerb or rail, that spanned the chasm with one curving spring of fifty feet.

It was an ancient defence of the Dwarves against any enemy that might capture the First Hall and the outer passages. They could only pass across it in single file.

A creature the size of the one in the movie couldn't fit on a bridge that was designed to make orcs have to pass single file.

Also, when Gandalf first engages the the Balrog on the bridge, they actually cross swords, and Gandalf momentarily drove back the Balrog with Glamdring. This, again, indicates a creature of more or less man size.

I'm of the opinion that artist (especially animators) over the years have mistaken the Balrogs shadow for immense size and for that matter wings.