Convert Foot-lamberts to Apostilbs (fL to asb)
1 foot-lambert (fL) = 10.76391042 apostilbs (asb). 1 asb = 0.09290304 fL. Example: 15 fL = 15 × 10.76391042 = 161.4586563 asb.
Also searched as foot-lamberts to asb, foot-lamberts in asb, foot-lamberts into apostilbs, fL to asb, fL in apostilbs, fL into apostilb, foot-lambert to apostilb, fL to apostilbs converter and how many apostilbs in a foot-lambert.
1 fL = 10.76391042 asb
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk foot-lambert to apostilb converter to paste a column from Excel.
How to Convert Foot-lambert to Apostilb
- 1 fL = 10.76391042 asb
- 1 asb = 0.09290304 fL
- Example: convert 15 fL to asb: 15 fL = 15 × 10.76391042 asb = 161.4586563 asb
Formula
asb = fL × 10.76391041671
Derivation from SI units:
- 1 fL = (1/π) cd/ft² ≈ 3.426 cd/m².
- 1 asb = (1/π) cd/m² ≈ 0.3183 cd/m².
- 1 fL = 3.426259099635 cd/m² ÷ 0.3183098861838 cd/m² per asb = 10.76391041671 asb
Both units are defined exactly, so the factor is exact. Foot-lambert definition: foot-lambert; Apostilb definition: apostilb.
Worked examples
- A reading of 10 fL converts to 107.6391042 asb.
10 fL × 10.76391042 = 107.6391042 asb - A value of 22 fL is 236.8060292 asb.
22 fL × 10.76391042 = 236.8060292 asb
Foot-lambert to Apostilb conversion table
| Foot-lamberts (fL) | Apostilbs (asb) |
|---|---|
| 1 fL | 10.76391042 asb |
| 4 fL | 43.05564167 asb |
| 7 fL | 75.34737292 asb |
| 10 fL | 107.6391042 asb |
| 14 fL | 150.6947458 asb |
| 16 fL | 172.2225667 asb |
| 22 fL | 236.8060292 asb |
| 30 fL | 322.9173125 asb |
| 50 fL | 538.1955208 asb |
| 100 fL | 1076.391042 asb |
Where it's used
Foot-lamberts are used for cinema projection standards (DCI 14 fL), while apostilbs appear in ophthalmic perimetry. Both measure luminance (brightness of a surface or screen), so the conversion is a fixed factor.
Foot-lambert to other luminance units
| Conversion | 1 fL equals |
|---|---|
| foot-lambert to apostilb | 10.76391042 asb |
| foot-lambert to nit | 3.4262591 cd/m² |
| foot-lambert to candela per square foot | 0.3183098862 cd/ft² |
| foot-lambert to candela per square inch | 0.002210485321 cd/in² |
| foot-lambert to stilb | 0.00034262591 sb |
| foot-lambert to lambert | 0.001076391042 L |
Frequently asked questions
How many apostilbs are in 1 foot-lambert?
1 fL = 10.76391042 asb.
How do I convert foot-lamberts to apostilbs?
Multiply the value in fL by 10.76391042. For example, 15 fL × 10.76391042 = 161.4586563 asb.
Is the fL to asb conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "footlambert".
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "apostilb".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Foot-lamberts to Apostilbs (fL to asb). Retrieved October 25, 2026, from https://scientificconverters.com/luminance/foot-lamberts-to-apostilbs/
IEEE
Scientific Converters, "Convert Foot-lamberts to Apostilbs (fL to asb)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/luminance/foot-lamberts-to-apostilbs/