 At the beginning of filming, Heather Menzies (qv) (Louisa) was  about three inches taller than Nicholas Hammond (I) (qv)  (Friedrich). He had to wear heel lifts to make him look taller. By  the end of the shoot, Nicolas Hammond had grown six inches (53" to  59"). He often filmed in no shoes and Charmian Carr (qv) had to  stand on a box to make her taller. All of the Von Trapp children  grew a lot during filming, so heel lifts and various camera tricks  were used to keep their heights steady.