Complex sentence: His artistic training always stood him in good stead in drawing diagrams of surpassing beauty and clarity whilst lecturing (students used to photograph the blackboard before it was erased) and in illustrating his books and papers.
Split into simpler sentences: His artistic training always stood him in good stead. He drew diagrams of beauty and clarity whilst lecturing (students used to photograph the blackboard before it was erased), and in his books and papers.