Convert Apostilbs to Foot-lamberts (asb to fL)
1 apostilb (asb) = 0.09290304 foot-lamberts (fL). 1 fL = 10.76391042 asb. Example: 15 asb = 15 × 0.09290304 = 1.3935456 fL.
Also searched as apostilbs to fL, apostilbs in fL, apostilbs into foot-lamberts, asb to fL, asb in foot-lamberts, asb into foot-lambert, apostilb to foot-lambert, asb to foot-lamberts converter and how many foot-lamberts in an apostilb.
1 asb = 0.09290304 fL
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk apostilb to foot-lambert converter to paste a column from Excel.
How to Convert Apostilb to Foot-lambert
- 1 asb = 0.09290304 fL
- 1 fL = 10.76391042 asb
- Example: convert 15 asb to fL: 15 asb = 15 × 0.09290304 fL = 1.3935456 fL
Formula
fL = asb × 0.09290304
or fL = asb ÷ 10.76391041671
Derivation from SI units:
- 1 asb = (1/π) cd/m² ≈ 0.3183 cd/m².
- 1 fL = (1/π) cd/ft² ≈ 3.426 cd/m².
- 1 asb = 0.3183098861838 cd/m² ÷ 3.426259099635 cd/m² per fL = 0.09290304 fL
Both units are defined exactly, so the factor is exact. Apostilb definition: apostilb; Foot-lambert definition: foot-lambert.
Worked examples
- A reading of 31.5 asb converts to 2.92644576 fL.
31.5 asb × 0.09290304 = 2.92644576 fL - A value of 1000 asb is 92.90304 fL.
1000 asb × 0.09290304 = 92.90304 fL
Apostilb to Foot-lambert conversion table
| Apostilbs (asb) | Foot-lamberts (fL) |
|---|---|
| 1 asb | 0.09290304 fL |
| 4 asb | 0.37161216 fL |
| 10 asb | 0.9290304 fL |
| 31.5 asb | 2.92644576 fL |
| 100 asb | 9.290304 fL |
| 318 asb | 29.54316672 fL |
| 1000 asb | 92.90304 fL |
| 3180 asb | 295.4316672 fL |
| 10000 asb | 929.0304 fL |
| 31800 asb | 2954.316672 fL |
Where it's used
Apostilbs are used for ophthalmic perimetry, while foot-lamberts appear in cinema projection standards (DCI 14 fL). Both measure luminance (brightness of a surface or screen), so the conversion is a fixed factor.
Apostilb to other luminance units
| Conversion | 1 asb equals |
|---|---|
| apostilb to foot-lambert | 0.09290304 fL |
| apostilb to nit | 0.3183098862 cd/m² |
| apostilb to candela per square foot | 0.02957195609 cd/ft² |
| apostilb to candela per square inch | 0.0002053608062 cd/in² |
| apostilb to stilb | 0.00003183098862 sb |
| apostilb to lambert | 0.0001 L |
Frequently asked questions
How many foot-lamberts are in 1 apostilb?
1 asb = 0.09290304 fL.
How do I convert apostilbs to foot-lamberts?
Multiply the value in asb by 0.09290304, or divide it by 10.76391042. For example, 15 asb × 0.09290304 = 1.3935456 fL.
Is the asb to fL 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, "apostilb".
- 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".
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 Apostilbs to Foot-lamberts (asb to fL). Retrieved October 25, 2026, from https://scientificconverters.com/luminance/apostilbs-to-foot-lamberts/
IEEE
Scientific Converters, "Convert Apostilbs to Foot-lamberts (asb to fL)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/luminance/apostilbs-to-foot-lamberts/