Photometry & ImagingFoot Lamberts to Apostilbs

Foot-Lamberts to Apostilbs

Snapshot

1 Foot-Lamberts equals 10.76391 Apostilbs. Conversion Encyclopedia uses the same fixed conversion basis across the calculator, common values, and reverse page for this page.

Reference basis: This conversion uses fixed luminance constants anchored to candela per square meter.
Example: For 5 Foot-Lamberts, the result equals 53.819552 Apostilbs.
Use the reverse page if you need the opposite direction with the same basis.

Use the interactive calculator below for custom values and the common-value table for quick checks.

Interactive conversion

Converter Calculator

10.76391 Apostilbs (asb)

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Machine access

Available to apps and AI agents

Foot-Lamberts to Apostilbs can be requested through Conversion Encyclopedia's structured interfaces by software and compatible AI agents. The identifiers below select the same calculation as the calculator.

Machine-readable identifiers

Conversion family: photometry-imaging
Source unit: foot_lamberts
Target unit: apostilbs

The JSON API and OpenAPI specification use the identifiers to reach the conversion engine. WebMCP lets compatible AI agents request the same calculation.

Example API request and response

POST /api/v1/convert

Request

{
  "family": "photometry-imaging",
  "value": 1,
  "from": "foot_lamberts",
  "to": "apostilbs"
}

Essential response

{
  "ok": true,
  "conversion": {
    "family": "photometry-imaging",
    "value": 1,
    "from": "foot_lamberts",
    "to": "apostilbs",
    "result": {
      "raw": 10.7639104166,
      "display": "10.76391"
    },
    "canonicalPath": "/photometry-imaging/foot-lamberts-to-apostilbs/"
  }
}

Full API documentation

Explanation

This page converts Foot-Lamberts into Apostilbs using fixed luminance constants anchored to candela per square meter. The direct answer, calculator, and common values table all follow the same factor.

Formula: Apostilbs = Foot-Lamberts × 10.76391. Why: legacy luminance units such as foot-lamberts, lamberts, apostilbs, and stilbs each use fixed cd/m² equivalents, so the calculator normalizes through candela per square meter before applying the target unit.

Foot-Lamberts (fL): a legacy luminance unit often used in projection and cinema display contexts.

Apostilbs (asb): a legacy luminance unit tied to a fixed candela-per-square-meter equivalent.

This route is useful when comparing modern display-brightness values with legacy luminance units used in projection, cinema, and older photometric references.

Because the route stays inside one cd/m2-based luminance model, the mirror page reverses the same constants without changing the underlying assumptions.

Method & Luminance Basis

Method basis: both units reduce through candela per square meter, then apply the fixed target-unit luminance relationship.
Applied factor: 1 Foot-Lamberts = 10.76391 Apostilbs.
Consistency rule: calculator output and table values use the same constants and rounding policy.

Common Conversion Values

Foot-Lamberts (fL)	Apostilbs (asb)
1	10.76391
5	53.819552
10	107.639104
25	269.09776
50	538.195521
100	1,076.391042
250	2,690.977604
500	5,381.955208
1,000	10,763.910417

Questions & answers

Frequently Asked Questions

How many apostilbs are in 1 foot-lamberts?

1 Foot-Lamberts equals 10.76391 Apostilbs on this page.

Why is Foot-Lamberts to Apostilbs useful in display and projection work?

This route is useful when comparing modern display-brightness values with legacy luminance units used in cinema, projection, calibration, and older imaging references.

When would I convert foot-lamberts to apostilbs?

This route is useful when comparing modern display-brightness values with legacy luminance units used in projection, cinema, and older photometric references.

How do I reverse Foot-Lamberts to Apostilbs?

Use the mirror Apostilbs to Foot-Lamberts route; it applies the inverse relationship with the same cd/m²-based luminance assumptions.