Martinus was not inclined to schooling, but in 1820 started his studies at the Royal Danish Academy of Fine Arts at 17 years of age. He studied under Christian August Lorentzen and Christoffer Wilhelm Eckersberg, a strong influence on a generation of artists during the Danish Golden Age. Rørbye was a favorite student of Eckersberg, and they formed a close association. He took to Eckersberg's careful attention to nature and his strivings to capture details realistically. He was also greatly influenced by Lorentzen's use of color.