Large format refers to any imaging format of 9 cm × 12 cm (3.5 in × 4.7
in) or larger. Large format is larger than "medium format", the 6 cm × 6 cm
(2.4 in × 2.4 in) or 6 cm × 9 cm (2.4 in × 3.5 in) size of Hasselblad, Mamiya,
Rollei, Kowa, and Pentax cameras (using 120- and 220-roll film), and much
larger than the 24 mm × 36 mm (0.94 in × 1.42 in) frame of 35 mm format.
The main advantage of a large format, film or digital, is a higher resolution
at the same pixel pitch, or the same resolution with larger pixels or grains
which allows each pixel to capture more light enabling exceptional low-light
capture. A 4×5 inch image (12.903 mm²) has about 15 times the area, and thus
15 times the total resolution, of a 35 mm frame (864 mm²).