Yousuf Karsh is one of my favorite portrait photographers. Yet until last week I had only seen his images in books and online, never in an actual exhibit. Fortunately I caught the last day of Portraits of Greatness at Boston’s Museum of Fine Arts. It’s now moving to the Art Institute of Chicago. It’s a great show whether your interest is in photography or in the monumental subjects. Everyone who was anyone — Winston Churchill, Pablo Picasso, Nikita Khrushchev, Ernest Hemingway, Audrey Hepburn, Albert Einstein, Fidel Castro, Mohammed Ali, and Jacqueline Kennedy – wanted to sit for Karsh. My two favorite stories: He refused to photograph George W. Bush, not because of political reasons but because George W. said he didn’t care what the image was long as Karsh was the man who pushed the shutter release. Such a comment showed no understanding, respect or appreciation for Karsh’s technique and the time it took to know and capture the essence of his subjects. The second is how he achieved the expression on Churchill’s face in the image above. At the last moment, Karsh plucked Churchill’s cigar from his lips, resulting in this stern expression. Two other things are worth noting for anyone constantly looking for inspiration. Karsh got his idea for controlling light by studying Rembrandt portraits on exhibit in Boston museums during his two years apprenticing in that city between 1928 and 1930. There he realized that the artist could control how light affected a subject. A year later he joined the Ottawa Little Theater, and the spectacle of stage lighting helped him learn how to achieve the intense moods that define his images. They remind us that, among other things, we all need constant exposure to new sources of inspiration if we’re to make something great.