He was known for his portrayal of society, urban life, and the jazz culture of San Francisco's Fillmore District in the 1940s and 1950s, as well as figures of the civil rights movement of the 1960s.

Born in Florida under segregation and trained at the California School of Fine Arts, he was the first African American student of photographer Ansel Adams.

[3][6] Johnson arrived in San Francisco in 1945, and lived for a time at Adams' home in the Sea Cliff neighborhood, becoming his first black student.

[5] Johnson became part of the School of Fine Art's "Golden Decade" (1945–1955), a group of photography students who trained under noted artists like Adams, Imogen Cunningham, Dorothea Lange and Minor White.

[3] Johnson soon discovered the Fillmore District, a neighborhood that was home to a large majority of the city's rapidly growing African American population.

[8] Shortly after, he was hired by the University of California, San Francisco (UCSF), where he worked in the personnel department to recruit minority employees.

He retired from UCSF in 1983,[9] and at age 65 returned to school, earning a master's degree in social work from Barry University in Miami, Florida.

[8] Exhibits of historic and contemporary photographs followed, including showings at California State University, Chico, the University of California, Merced,[10] and galleries in Atlanta[11] and Washington, D. C.[12] Johnson was the recipient of the Certificate of Honor in Photography from Mayor of San Francisco Gavin Newsom in 2004, and the Fillmore Heritage Pioneer Award in 2011.

He has served as chairman of the Mayor's Committee to Restore Haight Ashbury and as past president of the San Francisco African American Historical & Cultural Society.

[5] In later years, while remaining active in photography, he shifted towards preserving his legacy, and as of 2015 was working on a project on the black slaves of Sullivan's Island, South Carolina.