Specifications#
- Brand
- Phase One
- Model
- P25
- Camera type
- Medium-format digital
- Lens mount
- Mamiya 645
- Sensor size
- 62.4 × 41.6 mm (Medium format 53.4 × 40 mm)
- Crop factor
- 0.58×
Specifications merged from Wikidata and Lensfun. Spot an error? Tell us.
Sensor size compared#
Focal length equivalents & field of view#
Multiply any focal length by 0.58 to get the full-frame field of view. Angles are for a rectilinear lens focused at infinity.
| Lens on this camera | Full-frame equivalent | Horizontal | Vertical | Diagonal |
|---|---|---|---|---|
| 21 mm | 12 mm | 112.1° | 89.4° | 121.5° |
| 23 mm | 13 mm | 107.2° | 84.2° | 116.9° |
| 28 mm | 16 mm | 96.2° | 73.2° | 106.5° |
| 32 mm | 18 mm | 88.5° | 66.0° | 99.0° |
| 35 mm | 20 mm | 83.4° | 61.4° | 93.9° |
| 45 mm | 26 mm | 69.5° | 49.6° | 79.6° |
| 55 mm | 32 mm | 59.1° | 41.4° | 68.6° |
| 63 mm | 36 mm | 52.7° | 36.5° | 61.5° |
| 80 mm | 46 mm | 42.6° | 29.1° | 50.2° |
| 90 mm | 52 mm | 38.2° | 26.0° | 45.2° |
| 110 mm | 63 mm | 31.7° | 21.4° | 37.6° |
| 120 mm | 69 mm | 29.1° | 19.7° | 34.7° |
| 150 mm | 87 mm | 23.5° | 15.8° | 28.1° |
| 180 mm | 104 mm | 19.7° | 13.2° | 23.5° |
| 250 mm | 144 mm | 14.2° | 9.5° | 17.1° |
| 350 mm | 202 mm | 10.2° | 6.8° | 12.2° |
Depth of field table#
Total depth of field at each subject distance, using a circle of confusion of 52.0 µm (the 0.030 mm full-frame standard scaled by the crop factor).
| Focal | Aperture | 50.0 cm | 1.00 m | 2.00 m | 3.00 m | 5.00 m | 10.0 m | Hyperfocal |
|---|---|---|---|---|---|---|---|---|
| 38 mm | f/1.8 | 3.0 cm | 12.5 cm | 51.7 cm | 1.20 m | 3.59 m | 22.1 m | 15.5 m |
| 38 mm | f/2.8 | 4.7 cm | 19.6 cm | 82.3 cm | 1.97 m | 6.67 m | ∞ | 9.96 m |
| 38 mm | f/4 | 6.7 cm | 28.3 cm | 1.23 m | 3.13 m | 14.6 m | ∞ | 6.98 m |
| 38 mm | f/8 | 13.5 cm | 60.0 cm | 3.32 m | 18.8 m | ∞ | ∞ | 3.51 m |
| 75 mm | f/1.8 | 0.7 cm | 3.1 cm | 12.8 cm | 29.3 cm | 82.5 cm | 3.39 m | 60.2 m |
| 75 mm | f/2.8 | 1.1 cm | 4.8 cm | 20.0 cm | 45.7 cm | 1.30 m | 5.50 m | 38.7 m |
| 75 mm | f/4 | 1.6 cm | 6.8 cm | 28.6 cm | 65.7 cm | 1.88 m | 8.48 m | 27.1 m |
| 75 mm | f/8 | 3.1 cm | 13.7 cm | 58.1 cm | 1.36 m | 4.20 m | 31.8 m | 13.6 m |
| 128 mm | f/1.8 | 0.2 cm | 1.0 cm | 4.3 cm | 9.8 cm | 27.8 cm | 1.13 m | 175 m |
| 128 mm | f/2.8 | 0.3 cm | 1.5 cm | 6.7 cm | 15.3 cm | 43.4 cm | 1.77 m | 113 m |
| 128 mm | f/4 | 0.5 cm | 2.2 cm | 9.5 cm | 21.9 cm | 62.1 cm | 2.55 m | 78.9 m |
| 128 mm | f/8 | 0.9 cm | 4.4 cm | 19.1 cm | 44.0 cm | 1.26 m | 5.35 m | 39.5 m |
| 210 mm | f/1.8 | 0.1 cm | 0.3 cm | 1.5 cm | 3.6 cm | 10.2 cm | 41.6 cm | 471 m |
| 210 mm | f/2.8 | 0.1 cm | 0.5 cm | 2.4 cm | 5.5 cm | 15.8 cm | 64.7 cm | 303 m |
| 210 mm | f/4 | 0.1 cm | 0.7 cm | 3.4 cm | 7.9 cm | 22.6 cm | 92.5 cm | 212 m |
| 210 mm | f/8 | 0.3 cm | 1.5 cm | 6.8 cm | 15.8 cm | 45.3 cm | 1.86 m | 106 m |
Equivalent aperture#
Exposure is identical at the same f-number on any format; equivalence only describes depth of field and total light.
Night-sky exposure limits#
Longest exposure before stars trail. The NPF rule accounts for pixel pitch and is stricter than the classic 500 rule — use it for pin-sharp stars on high-resolution sensors. (NPF needs a known resolution and is omitted here.)
| Focal length | 500 rule |
|---|---|
| 24 mm (14 mm eq.) | 36.1 s |
| 35 mm (20 mm eq.) | 24.8 s |
| 42 mm (24 mm eq.) | 20.6 s |
| 61 mm (35 mm eq.) | 14.2 s |
| 87 mm (50 mm eq.) | 10.0 s |
Handheld shutter speed guide#
The reciprocal rule uses the equivalent focal length. High-resolution sensors may need one stop faster than this for pixel-sharp results.
| Focal length | No stabilisation (1/equiv. focal) | With 3-stop IS | With 5-stop IBIS |
|---|---|---|---|
| 42 mm | 1/25 s | 0.3 s | 1.3 s |
| 87 mm | 1/50 s | 1/6 s | 0.6 s |
| 173 mm | 1/100 s | 1/13 s | 0.3 s |
| 347 mm | 1/200 s | 1/25 s | 1/6 s |
Similar cameras#
Other Medium format 53.4 × 40 mm cameras from around the same time.
- Canon AE-1 1976
- Canon AE-1 Program 1981
- Canon AL-1 1982
- Canon A-1 1978
- Canon New F-1 1981
- Canon T70
- Petri TTL
- Hasselblad 500 mech.
Frequently asked questions#
What is the crop factor of the Phase One P25?
The Phase One P25 has a crop factor of 0.58× relative to 35 mm full frame (diagonal 75.0 mm vs 43.3 mm).
What size is the Phase One P25 sensor?
62.4 × 41.6 mm (Medium format 53.4 × 40 mm), an area of 2595 mm² — 300% of full frame.
Is the Phase One P25 full frame?
No — its sensor is larger than full frame (medium format).
What lens mount does the Phase One P25 use?
The Phase One P25 uses the Mamiya 645 (flange distance 63.30 mm).
How long can I expose the night sky with the Phase One P25?
With a 35 mm lens (20 mm equivalent) the 500 rule gives 25 s.
Sources & licences#
- Wikidata Q140487682 — CC0
- Lensfun camera database — CC BY-SA 3.0
Last updated October 03, 2026 · How we calculate · Sources