He has shot album covers for hip hop and R&B performers including Dr. Dre,[1] Jay Z, Aaliyah, Outkast, Nas, Nicki Minaj, Brandy Norwood and Kendrick Lamar.

[2] Mannion studied at Kenyon College in Ohio graduating with honors.

Mannion worked for a year with photographer Richard Avedon[3] in his Manhattan studio.

Mannion also worked with photographers Ben Watts, Steven Klein, and Marc Hom.

In 1996, he photographed Brooklyn rapper Jay-Z for Reasonable Doubt.