Series author George R. R. Martin gives a commentary for episode 9, “Blackwater,” the episode he wrote, and while the commentary begins with Martin connecting events in the show with how they originated in the book, once the battle begins he goes off on a lonnnng tangent about… helmets.
Specifically, Martin wanted the main characters to be wearing helmets during the battle scenes. (Sandor Clegane, Tyrion, Stannis, and Lancel Lannister all go without helmets during the battle scene.) The author explains his reasons why (it’s far more realistic, and Clegane’s helmet is really cool) but also acknowledges that he knows why they aren’t wearing helmets (it’s a visual medium and you need to be able to see the main character’s faces).
And yet…! Any time the battle scenes reappear, Martin brings up the helmet issue again. At one point he’s simply repeating “no helmet, helmet, no helmet…” as the camera pans across a bunch of soldiers fighting.— The Best Stuff Revealed in the Game of Thrones Season 2 Blu-ray Set (via lyrabelacqua)