Which "notice event" in the book is it? There's the one in daylight where Merry, Frodo, and Strider see the BR's on the road from the top of Weathertop. In the movie the one time they spot them is at night. Also, in the book I got the impression that they "felt" them before they saw them.
That's the one I was thinking of.
they "felt" them before they saw them
In many ways, the early parts of (the book) LOTR are my favorites, The subtle and more mysterious menace projected by the black riders fills me with greater dread than the hordes of Orcs that appear later. Their presence right in the shire evokes memories of my boyhood in the 50's in rural Virginia right around Halloween. Walking outside with my mother, feeling a hint of the coming winter chill in the air, watching the leaves tumble and fall and hearing stories about the strange souls that would be out later.
I also thought that the Bucklebury ferry scene in the book was more spooky than the movie version. Seeing an indistinct shadowy figure on the far shore was pretty menacing and mysterious. I can see where it might not have worked as well on film, though. I did think it was very dramatic there in the movie when the one rider was suddenly joined by two more. Their unworldly screeches were chilling.