The Canon PowerShot G1 X Mark III uses the built-in lens (fixed-lens camera) with a 1.61× crop factor (about 22.3 × 14.9 mm sensor). Below: equivalent focal lengths, maximum shutter speeds for sharp stars, a hyperfocal distance chart and how to check the shutter count.
Equivalent focal length & field of view
| Lens focal length | Full-frame equivalent | Diagonal FOV | Horizontal FOV |
|---|---|---|---|
| 8 mm | 13 mm | 118.4° | 108.7° |
| 10 mm | 16 mm | 106.6° | 96.2° |
| 12 mm | 19 mm | 96.4° | 85.8° |
| 14 mm | 23 mm | 87.5° | 77.1° |
| 16 mm | 26 mm | 79.9° | 69.7° |
| 18 mm | 29 mm | 73.4° | 63.6° |
| 20 mm | 32 mm | 67.7° | 58.3° |
| 24 mm | 39 mm | 58.4° | 49.8° |
| 28 mm | 45 mm | 51.2° | 43.4° |
| 35 mm | 56 mm | 41.9° | 35.3° |
| 50 mm | 81 mm | 30.0° | 25.1° |
| 85 mm | 137 mm | 17.9° | 14.9° |
| 135 mm | 218 mm | 11.3° | 9.4° |
| 200 mm | 323 mm | 7.7° | 6.4° |
| 300 mm | 484 mm | 5.1° | 4.3° |
| 400 mm | 645 mm | 3.8° | 3.2° |
Multiply by the 1.61× crop factor for the full-frame equivalent field of view.
Milky Way exposure: NPF and 500 rule
| Focal length | NPF @ f/1.8 | NPF @ f/2.8 | Strict NPF @ f/2.8 | 500 rule |
|---|---|---|---|---|
| 8 mm | 22.5 s | 26.9 s | 14.5 s | 38.7 s |
| 10 mm | 18.0 s | 21.5 s | 11.6 s | 31.0 s |
| 12 mm | 15.0 s | 17.9 s | 9.7 s | 25.8 s |
| 14 mm | 12.9 s | 15.4 s | 8.3 s | 22.1 s |
| 16 mm | 11.2 s | 13.4 s | 7.3 s | 19.4 s |
| 18 mm | 10.0 s | 11.9 s | 6.5 s | 17.2 s |
| 20 mm | 9.0 s | 10.8 s | 5.9 s | 15.5 s |
| 24 mm | 7.5 s | 9.0 s | 4.9 s | 12.9 s |
| 28 mm | 6.4 s | 7.7 s | 4.2 s | 11.1 s |
| 35 mm | 5.1 s | 6.1 s | 3.4 s | 8.9 s |
NPF = (35 × f-number + 30 × pixel pitch) ÷ focal length, with a pixel pitch of 3.9 µm (typical for this format — exact resolution not in our database). The strict version (Michaud's detailed NPF for the galactic core) gives pin-point stars at 100% view; the 500 rule is a loose rule of thumb that shows trailing on modern sensors.
Hyperfocal distance chart
| Focal length | f/2.8 | f/5.6 | f/8 | f/11 | f/16 |
|---|---|---|---|---|---|
| 10 mm | 1.9 m | 1.0 m | 0.7 m | 0.5 m | 0.3 m |
| 14 mm | 3.8 m | 1.9 m | 1.3 m | 1.0 m | 0.7 m |
| 16 mm | 4.9 m | 2.5 m | 1.7 m | 1.3 m | 0.9 m |
| 18 mm | 6.2 m | 3.1 m | 2.2 m | 1.6 m | 1.1 m |
| 20 mm | 7.7 m | 3.9 m | 2.7 m | 2.0 m | 1.4 m |
| 24 mm | 11 m | 5.6 m | 3.9 m | 2.8 m | 2.0 m |
| 28 mm | 15 m | 7.6 m | 5.3 m | 3.9 m | 2.7 m |
| 35 mm | 24 m | 12 m | 8.3 m | 6.0 m | 4.2 m |
Focus at the hyperfocal distance and everything from half that distance to infinity is acceptably sharp (circle of confusion 0.0186 mm). Use the hyperfocal calculator for other settings.
How to check the Canon PowerShot G1 X Mark III shutter count
Canon stores the count only for some models (mostly recent mirrorless bodies such as the R-series). Older EOS DSLRs usually need a tethered utility that reads the counter over USB. Try `exiftool -ShutterCount -MechanicalShutterCount image.cr3`.
ExifTool tag: ShutterCount / MechanicalShutterCount. Always test an original, unedited file straight from the card.
Where to buy
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