Astrophotography Calculator
Canon EOS R5
Sensor: 36x24mm, 45MP, 4.38um pitch
Crop: Full Frame
mm
f/
4 — Rural/suburban transition
Target Type
NPF Rule9.6s
500 Rule20.8s
500 Rule (Crop)20.8s
Recommended Sub-Exposure (Bortle 4, Milky Way)7s
Stacking Recommendations
Based on 7s sub-exposures for Milky Way imaging
| Frames↕ | Total Time (min)↕ | SNR Gain↕ | Equiv. Single Exp.↕ |
|---|---|---|---|
| 10 | 1.2 | 3.2x | 1m 10s |
| 20 | 2.3 | 4.5x | 2m 20s |
| 50 | 5.8 | 7.1x | 5m 50s |
Rule Comparison
NPF Rule (most accurate)9.6s
500 Rule (full-frame)20.8s
500 Rule (crop-adjusted)20.8s
The NPF rule accounts for pixel pitch and aperture for more precise results. Use the most conservative (shortest) value for sharp stars.