 The cards were lit by electric light bulbs inside the machine, a system devised by Arthur Marvin's brother, Henry, one of the founders of the Biograph company.Earlier machines had relied on reflected natural light.To avoid violating Edison's patents, Biograph cameras from 1895 to 1902 used a large-format film measuring 2-23/32 inches (68 mm) wide, with an image area of 2 × 2½ inches, four times that of Edison's 35 mm format.