Under law, the photographer who will own copyright on any photos he/she has taken unless the photographer is an employee of the company the pictures are taken for, or is an employee of a company told or hired to take the photos, or if there’s an agreement with another person to let him/her use the pictures.
In all other situations, the photographer will own the copyright. If the photographer is paid for his/her work, the payment will be for the photographer’s time. The copyright to the photos will be the photographers, and any copys without permission would be an infringement of copyright.