Photometry
phtonox
Convert phots (ph) to nox (nox).
Factor1 ph = 1e+7 nox
Converter
ph
Accepts numbers or expressions, e.g. 150 + 14.7
Result
nox
Rendered to 6 significant figures.
Formula
Formula
nox = ph × 1e+7
Multiply any value in phots by 1e+7 to obtain the value in nox.
Worked example
Convert 1 ph to nox.
- 01Start with 1 ph.
- 02Multiply by the conversion factor: 1 × 1e+7 = 1e+7 nox.
Result1 ph = 1e+7 nox
Conversion table
| ph | nox |
|---|---|
| 1 | 1e+7 |
| 2 | 2e+7 |
| 5 | 5e+7 |
| 10 | 1e+8 |
| 20 | 2e+8 |
| 50 | 5e+8 |
| 100 | 1e+9 |
| 200 | 2e+9 |
| 500 | 5e+9 |
| 1000 | 1e+10 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from ph to nox?
1 ph equals 1e+7 nox. To convert, multiply the value in phots by 1e+7.
How do I convert 1 ph to nox?
1 ph = 1e+7 nox. For any value, multiply by 1e+7.
How do I convert nox back to ph?
Divide by the same factor — or equivalently, multiply by 1e-7. So 1 nox = 1e-7 ph.
When would I need to convert phot to nox?
Illuminance conversions between ph and nox are used in lighting design, workplace safety assessments, and photographic exposure work. Lux is the SI standard for international codes; foot-candles remain common in US lighting specifications.
Is the conversion exact?
The factor shown is precise to at least 7 significant figures. For most process-engineering work this is far better than instrument accuracy. For metrology or trade applications, refer to the relevant national standard (NIST, BIPM, ISO 80000).