Photometry
fLtoasb
Convert foot-lamberts (fL) to apostilbs (asb).
Factor1 fL = 10.76391 asb
Converter
fL
Accepts numbers or expressions, e.g. 150 + 14.7
Result
asb
Rendered to 6 significant figures.
Formula
Formula
asb = fL × 10.76391
Multiply any value in foot-lamberts by 10.76391 to obtain the value in apostilbs.
Worked example
Convert 100 fL to asb.
- 01Start with 100 fL.
- 02Multiply by the conversion factor: 100 × 10.76391 = 1076.39 asb.
Result100 fL = 1076.39 asb
Conversion table
| fL | asb |
|---|---|
| 1 | 10.764 |
| 2 | 21.528 |
| 5 | 53.82 |
| 10 | 107.64 |
| 20 | 215.28 |
| 50 | 538.2 |
| 100 | 1076.4 |
| 200 | 2152.8 |
| 500 | 5382 |
| 1000 | 10764 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from fL to asb?
1 fL equals 10.76391 asb. To convert, multiply the value in foot-lamberts by 10.76391.
How do I convert 1 fL to asb?
1 fL = 10.7639 asb. For any value, multiply by 10.76391.
How do I convert asb back to fL?
Divide by the same factor — or equivalently, multiply by 0.09290304. So 1 asb = 0.092903 fL.
When would I need to convert foot-lambert to apostilb?
Luminance conversions between fL and asb are used in display engineering, road and traffic-signal design, and photometric measurement of luminous surfaces. cd/m² (nit) is the SI standard; foot-lambert and stilb appear in legacy datasheets and specialist optics work.
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).