foot-lambert: meaning, definition, pronunciation and examples
Very LowTechnical/Scientific
Quick answer
What does “foot-lambert” mean?
A unit of luminance, equal to one lumen per square foot.
Audio
Pronunciation
Definition
Meaning and Definition
A unit of luminance, equal to one lumen per square foot.
In technical contexts, it measures the brightness of a surface emitting or reflecting light, often used for displays and screens. Historically derived from the brightness of a perfectly diffusing surface illuminated by one foot-candle.
Dialectal Variation
British vs American Usage
Differences
The unit is used in both regions, but British technical standards may increasingly favour the SI unit candela per square metre (nit). The hyphenated spelling 'foot-lambert' is standard in both.
Connotations
Purely technical, with no cultural connotations. May be perceived as slightly archaic as modern standards shift to SI units.
Frequency
Extremely low frequency in general language. Slightly more likely to be encountered in American technical documentation for display specifications (e.g., TVs, monitors).
Grammar
How to Use “foot-lambert” in a Sentence
The [display] has a luminance of [number] foot-lamberts.Measure the [surface] brightness in foot-lamberts.Vocabulary
Collocations
Examples
Examples of “foot-lambert” in a Sentence
verb
British English
- The display was calibrated to foot-lambert specifications.
- We need to foot-lambert the readings for the legacy report.
American English
- The engineer foot-lamberts all luminance measurements for this project.
- Older models foot-lamberts their output, unlike newer ones.
adverb
British English
- The screen was measured foot-lambert precisely.
- The values are expressed foot-lambert.
American English
- Calibrate the monitor foot-lambert accurately.
- The report lists luminance foot-lambert.
adjective
British English
- The foot-lambert reading was taken under controlled conditions.
- We require a foot-lambert calibration certificate.
American English
- Check the foot-lambert value on the spec sheet.
- The foot-lambert measurement is standard for this industry.
Usage
Meaning in Context
Business
Rare, except in very specific industries like display manufacturing or calibration services.
Academic
Used in physics, engineering, and optics papers, especially older publications or those referencing US standards.
Everyday
Virtually never used.
Technical
Primary domain. Used in specifications for CRT/LCD/OLED displays, photometric reports, and lighting engineering.
Vocabulary
Synonyms of “foot-lambert”
Strong
Neutral
Weak
Vocabulary
Antonyms of “foot-lambert”
Watch out
Common Mistakes When Using “foot-lambert”
- Writing as one word ('footlambert') or without a hyphen.
- Confusing it with the foot-candle (a unit of illuminance, not luminance).
- Pronouncing 'lambert' as /læmˈbɜːrt/ instead of /ˈlæmbərt/.
FAQ
Frequently Asked Questions
No, it is a non-SI unit of luminance based on the foot. The SI unit is the candela per square metre (cd/m²), also called a 'nit'.
Primarily in older technical documents, some US display specifications (especially for CRTs), and in certain fields like aerospace or military lighting standards.
One foot-lambert (fL) is approximately equal to 3.426 candelas per square metre (nits). So, multiply foot-lamberts by 3.426 to get nits.
A foot-candle is a unit of illuminance (light falling *on* a surface). A foot-lambert is a unit of luminance (light emitted or reflected *by* a surface). They are related but measure different things.
A unit of luminance, equal to one lumen per square foot.
Foot-lambert is usually technical/scientific in register.
Foot-lambert: in British English it is pronounced /ˈfʊt ˌlæmbət/, and in American English it is pronounced /ˈfʊt ˌlæmbərt/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “None”
Learning
Memory Aids
Mnemonic
Think of a LAMBERT the sheep, standing on one FOOT. The light from a lamp makes his wool bright, measured in foot-lamberts.
Conceptual Metaphor
BRIGHTNESS IS A MEASURABLE QUANTITY (like height or weight).
Practice
Quiz
What does a foot-lambert measure?