220 Roll Film (Double-Length Medium Format)
Direct Answer
220 Film (standardized under ISO 732, introduced in 1965) is a double-length medium format roll film that yields twice the exposures of 120 film (24 exposures at 6×6 cm, 20 exposures at 6×7 cm). By eliminating the backing paper along the body of the film (retaining paper only at the black leader and trailer), twice as much film fits onto the same 25mm spool.
Source: ISO 732:2000 (120 and 220 Roll Film Standards)
Specs
| Film Strip Width | 61.5 ± 0.5 mm |
| Total Film Strip Length | Approx. 1650 mm (65.0 in — double the length of 120 film) |
| Backing Paper Structure | Leader and trailer paper only (no backing paper behind the active emulsion) |
| 6×6 cm Frame Yield | 24 exposures (vs 12 on 120 film) |
| 6×7 cm Frame Yield | 20 exposures (vs 10 on 120 film) |
| 6×4.5 cm Frame Yield | 30 to 32 exposures |
| Pressure Plate Setting | Requires flipping the camera pressure plate to '220' position (compensates for missing paper thickness to prevent focal shift) |
The Pressure Plate Focus Shift
Because 220 film lacks backing paper behind the emulsion, the overall thickness of the roll is reduced. Camera backs (such as Hasselblad A24 or Mamiya RZ67 220 backs) feature an adjustable pressure plate: failing to switch the plate to the '220' position pushes the film slightly out of the calibrated focal plane, causing subtle focus errors.