56×41.5 mm
Dimensions
0.62×
Crop factor
2324 mm²
Area (269% of FF)
+1.4
Stops of light vs full frame
4:3
Aspect ratio
48.3 µm
Circle of confusion
About 6 × 4.5 cm (645) film#
Smallest 120-film frame: 15–16 exposures per roll.
Typical cameras: Mamiya 645, Pentax 645, Fujifilm GA645.
Compared to other formats#
Lens needed for the same framing#
| Full-frame focal length | Equivalent on 6 × 4.5 cm (645) film | Horizontal angle |
|---|---|---|
| 14 mm | 22.6 mm | 102.3° |
| 24 mm | 38.7 mm | 71.8° |
| 35 mm | 56.4 mm | 52.8° |
| 50 mm | 80.5 mm | 38.3° |
| 85 mm | 136.9 mm | 23.1° |
| 135 mm | 217.5 mm | 14.7° |
| 200 mm | 322.2 mm | 9.9° |
Equivalent aperture for depth of field#
| On 6 × 4.5 cm (645) film | Full-frame equivalent |
|---|---|
| f/1.4 | f/0.9 |
| f/2 | f/1.2 |
| f/2.8 | f/1.7 |
| f/4 | f/2.5 |
| f/5.6 | f/3.5 |
| f/8 | f/5.0 |
Cameras with a 6 × 4.5 cm (645) film frame#
3 cameras in our database.
Frequently asked questions#
What is the crop factor of 6 × 4.5 cm (645) film?
0.62× (diagonal 69.7 mm vs 43.3 mm for full frame).
How big is a 6 × 4.5 cm (645) film sensor?
56 × 41.5 mm, an area of 2324 mm².
Is 6 × 4.5 cm (645) film good in low light?
At the same exposure it gathers 1.4 stops more total light than full frame, so expect roughly that much less visible noise at equal print size. Modern processing narrows but doesn't erase the gap.
Last updated October 03, 2026 · How we calculate · Sources