 The earliest cameras produced in significant numbers used sensitised glass plates were "plate cameras".Light entered a lens mounted on a lens board which was separated from the plate by an extendible bellows.There were simple box cameras for glass plates but also single-lens reflex cameras with interchangeable lenses and even for color photography (Autochrome Lumière).Many of these cameras had controls to raise or lower the lens and to tilt it forwards or backwards to control perspective.