Complex sentence: He was present during the taking of the famous Jazz photograph "A Great Day in Harlem" in 1958, however he famously was sitting down resting when the selected shot was taken, leaving him out of the final picture.
Split into simpler sentences: He was present during the taking of the famous Jazz photograph "A Great Day in Harlem" in 1958. However, he famously was sitting down resting when the selected shot was taken, leaving him out of the final picture.