James Ross first appears in the Edinburgh trade directories of the early 1840s as a portrait and landscape painter. He then set up in business as a photographer with a studio in the National Monument in Calton Hill where he was joined in partnership with John Thomson. They began practising with the daguerreotype and calotype proceses, but were amongst the first to adopt the albumen process in 1849. The same year, they sent an album to Windsor Castle and were appointed 'Photographers to the Queen'. In 1851, they won a medal in the Great Exhibition in London. In the 1850s and 60s, they specialised in studio portraits. James Ross had a second partnership with Thomas Pringle.