Large format cameras are manual-focus view cameras that use sheet film to produce images significantly larger than other formats. (The most popular large format cameras produce images 100 x 120mm in size, 13 times the area of a standard 35mm camera image.) Similarly, large format cameras are the largest contemporary cameras, requiring tripods to hold them steady, and bellows to adjust focal lengths. Large format cameras are widely considered the most "old-fashioned" types of cameras, having changed relatively little over the past century.