I'd always thought (after dozens of viewings) that Hitchcock's astonishing shift from James Stewart's POV to Kim Novak's begins with Judy's look into the camera and her writing, then tearing up, her confession letter to Scottie, almost 100 minutes into Vertigo. No.
The movie is pregnant with her tenderness and sorrow from the start. Perhaps the whole work is born from her actual fatal descent off the bell-tower, looking back. For how could something like this come from a man as hard-headed, humorless, cold, prosaic, and contemptuous of women (Madeleine at first, Midge, Ellen Corby at the McKittrick) as is the ex-detective?