Specifications#
- Brand
- Canon
- Model
- PowerShot A640
- Camera type
- Compact
- Sensor size
- 7.1 × 5.6 mm (1/1.7" sensor)
- Crop factor
- 4.79×
Specifications merged from Wikidata, Lensfun and openMVG. Spot an error? Tell us.
Sensor size compared#
Focal length equivalents & field of view#
Multiply any focal length by 4.79 to get the full-frame field of view. For fixed-lens cameras use the real focal length printed on the lens (e.g. “6.1–18.3 mm”), not the 35 mm equivalent.
| Lens on this camera | Full-frame equivalent | Horizontal | Vertical | Diagonal |
|---|---|---|---|---|
| 4 mm | 19 mm | 83.3° | 69.7° | 96.9° |
| 4.5 mm | 22 mm | 76.6° | 63.5° | 90.2° |
| 5 mm | 24 mm | 70.8° | 58.2° | 84.2° |
| 6 mm | 29 mm | 61.3° | 49.8° | 73.9° |
| 8 mm | 38 mm | 47.9° | 38.4° | 58.9° |
| 10 mm | 48 mm | 39.1° | 31.1° | 48.6° |
| 12 mm | 57 mm | 33.0° | 26.1° | 41.2° |
| 15 mm | 72 mm | 26.7° | 21.0° | 33.5° |
| 20 mm | 96 mm | 20.2° | 15.9° | 25.4° |
| 25 mm | 120 mm | 16.2° | 12.7° | 20.5° |
| 30 mm | 144 mm | 13.5° | 10.6° | 17.1° |
| 40 mm | 192 mm | 10.2° | 8.0° | 12.9° |
| 50 mm | 240 mm | 8.1° | 6.4° | 10.3° |
| 70 mm | 335 mm | 5.8° | 4.6° | 7.4° |
| 100 mm | 479 mm | 4.1° | 3.2° | 5.2° |
| 150 mm | 719 mm | 2.7° | 2.1° | 3.4° |
Depth of field table#
Total depth of field at each subject distance, using a circle of confusion of 6.3 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 |
|---|---|---|---|---|---|---|---|---|
| 4 mm | f/2 | 45.7 cm | 3.98 m | ∞ | ∞ | ∞ | ∞ | 1.28 m |
| 4 mm | f/2.8 | 77.2 cm | ∞ | ∞ | ∞ | ∞ | ∞ | 91.6 cm |
| 4 mm | f/4 | 1.96 m | ∞ | ∞ | ∞ | ∞ | ∞ | 64.3 cm |
| 4 mm | f/8 | ∞ | ∞ | ∞ | ∞ | ∞ | ∞ | 32.3 cm |
| 9 mm | f/2 | 7.6 cm | 31.4 cm | 1.36 m | 3.53 m | 19.1 m | ∞ | 6.48 m |
| 9 mm | f/2.8 | 10.8 cm | 45.0 cm | 2.12 m | 6.69 m | ∞ | ∞ | 4.63 m |
| 9 mm | f/4 | 15.5 cm | 67.7 cm | 3.97 m | 38.4 m | ∞ | ∞ | 3.24 m |
| 9 mm | f/8 | 33.5 cm | 1.96 m | ∞ | ∞ | ∞ | ∞ | 1.63 m |
| 15 mm | f/2 | 2.7 cm | 11.0 cm | 44.7 cm | 1.03 m | 3.01 m | 16.1 m | 18.0 m |
| 15 mm | f/2.8 | 3.8 cm | 15.4 cm | 63.4 cm | 1.48 m | 4.58 m | 39.5 m | 12.8 m |
| 15 mm | f/4 | 5.4 cm | 22.2 cm | 92.9 cm | 2.24 m | 8.02 m | ∞ | 9.00 m |
| 15 mm | f/8 | 10.9 cm | 46.1 cm | 2.20 m | 7.14 m | ∞ | ∞ | 4.51 m |
| 25 mm | f/2 | 1.0 cm | 3.9 cm | 15.9 cm | 35.9 cm | 1.01 m | 4.16 m | 49.9 m |
| 25 mm | f/2.8 | 1.3 cm | 5.5 cm | 22.2 cm | 50.4 cm | 1.42 m | 6.07 m | 35.7 m |
| 25 mm | f/4 | 1.9 cm | 7.8 cm | 31.9 cm | 72.6 cm | 2.08 m | 9.52 m | 25.0 m |
| 25 mm | f/8 | 3.8 cm | 15.7 cm | 65.0 cm | 1.52 m | 4.74 m | 44.3 m | 12.5 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 |
|---|---|
| 4 mm (19 mm eq.) | 26.1 s |
| 5 mm (24 mm eq.) | 20.9 s |
| 6 mm (29 mm eq.) | 17.4 s |
| 7 mm (34 mm eq.) | 14.9 s |
| 10 mm (48 mm eq.) | 10.4 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 |
|---|---|---|---|
| 5 mm | 1/25 s | 0.3 s | 1.3 s |
| 10 mm | 1/50 s | 1/6 s | 0.6 s |
| 21 mm | 1/100 s | 1/13 s | 0.3 s |
| 42 mm | 1/200 s | 1/25 s | 1/6 s |
Lens#
The Canon PowerShot A640 has a built-in, non-interchangeable lens. Use the real focal length of that lens with the tables above; its full-frame equivalent is that number × 4.79.
Similar cameras#
Other 1/1.7" cameras from around the same time.
Frequently asked questions#
What is the crop factor of the Canon PowerShot A640?
The Canon PowerShot A640 has a crop factor of 4.79× relative to 35 mm full frame (diagonal 9.0 mm vs 43.3 mm).
What size is the Canon PowerShot A640 sensor?
7.1 × 5.6 mm (1/1.7"), an area of 40 mm² — 5% of full frame.
Is the Canon PowerShot A640 full frame?
No — its sensor is 1/1.7", which is 21.8× smaller in area than full frame.
How long can I expose the night sky with the Canon PowerShot A640?
With a 5 mm lens (24 mm equivalent) the 500 rule gives 21 s.
Sources & licences#
- Wikidata Q10887025 — CC0
- Lensfun camera database — CC BY-SA 3.0
- openMVG sensor width database — MPL-2.0
Last updated October 03, 2026 · How we calculate · Sources