['However', ',', 'the', 'key', 'attraction', 'of', 'SfM', '–', 'MVS', 'is', 'that', 'the', 'required', 'input', 'can', 'be', 'taken', 'by', 'anyone', 'with', 'a', 'digital', 'camera', 'and', 'modest', 'prior', 'training', 'about', 'the', 'required', 'number', 'and', 'overlap', 'of', 'photographs', '.']