 A modified ROM was required to use autofocus with the 21 mm and 35 mm lenses; modified G1 cameras are marked with a green sticker inside the film door, and are known as "green label" G1s to distinguish them from unmodified "silver label" G1s.No G1 could accept the 35–70 mm, as it was a seven contact electrical connection and the G1 only features five contacts.Because the viewfinder was limited to the angle of view corresponding to the 28 mm Biogon, the 16 mm Hologon and 21 mm Biogon lenses were each bundled with a separate accessory viewfinder that mounted in the hotshoe.