Convert Lamberts to Apostilbs (L to asb)
1 lambert (L) = 10000 apostilbs (asb). 1 asb = 0.0001 L. Example: 15 L = 15 × 10000 = 150000 asb.
Also searched as lamberts to asb, lamberts in asb, lamberts into apostilbs, L to asb, L in apostilbs, L into apostilb, lambert to apostilb, L to apostilbs converter and how many apostilbs in a lambert.
1 L = 10000 asb
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk lambert to apostilb converter to paste a column from Excel.
How to Convert Lambert to Apostilb
- 1 L = 10000 asb
- 1 asb = 0.0001 L
- Example: convert 15 L to asb: 15 L = 15 × 10000 asb = 150000 asb
Formula
asb = L × 10000
Derivation from SI units:
- 1 L = (1/π) cd/cm² ≈ 3183 cd/m².
- 1 asb = (1/π) cd/m² ≈ 0.3183 cd/m².
- 1 L = 3183.098861838 cd/m² ÷ 0.3183098861838 cd/m² per asb = 10000 asb
Both units are defined exactly, so the factor is exact. Lambert definition: lambert; Apostilb definition: apostilb.
Worked examples
- A reading of 2 L converts to 20000 asb.
2 L × 10000 = 20000 asb - A value of 20 L is 200000 asb.
20 L × 10000 = 200000 asb
Lambert to Apostilb conversion table
| Lamberts (L) | Apostilbs (asb) |
|---|---|
| 0.1 L | 1000 asb |
| 0.5 L | 5000 asb |
| 1 L | 10000 asb |
| 2 L | 20000 asb |
| 5 L | 50000 asb |
| 10 L | 100000 asb |
| 20 L | 200000 asb |
| 50 L | 500000 asb |
| 100 L | 1000000 asb |
| 1000 L | 10000000 asb |
Where it's used
Lamberts are used for older vision-science literature, while apostilbs appear in ophthalmic perimetry. Both measure luminance (brightness of a surface or screen), so the conversion is a fixed factor.
Lambert to other luminance units
| Conversion | 1 L equals |
|---|---|
| lambert to apostilb | 10000 asb |
| lambert to nit | 3183.098862 cd/m² |
| lambert to foot-lambert | 929.0304 fL |
| lambert to candela per square foot | 295.7195609 cd/ft² |
| lambert to candela per square inch | 2.053608062 cd/in² |
| lambert to stilb | 0.3183098862 sb |
Frequently asked questions
How many apostilbs are in 1 lambert?
1 L = 10000 asb.
How do I convert lamberts to apostilbs?
Multiply the value in L by 10000. For example, 15 L × 10000 = 150000 asb.
Is the L to asb conversion exact?
Yes. Both units are defined exactly, and 1 L is exactly 10000 asb.
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, "lambert".
- 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 Lamberts to Apostilbs (L to asb). Retrieved October 25, 2026, from https://scientificconverters.com/luminance/lamberts-to-apostilbs/
IEEE
Scientific Converters, "Convert Lamberts to Apostilbs (L to asb)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/luminance/lamberts-to-apostilbs/