foot-candle: meaning, definition, pronunciation and examples
Very LowTechnical/Specialized
Quick answer
What does “foot-candle” mean?
A unit of illuminance equal to the illumination produced by a uniform source of one candela on a surface one foot away.
Audio
Pronunciation
Definition
Meaning and Definition
A unit of illuminance equal to the illumination produced by a uniform source of one candela on a surface one foot away.
A technical measurement of light intensity used in lighting design, photography, and architecture to quantify how much light falls on a surface.
Dialectal Variation
British vs American Usage
Differences
The term is used in both varieties but is more common in American technical contexts due to the persistence of imperial units. In the UK, the metric unit 'lux' is strongly preferred in official and modern technical writing.
Connotations
In both varieties, it connotes a specialized, often older or traditional technical field (e.g., legacy building codes, certain photography manuals). In the UK, it may additionally connote an American influence or outdated practice.
Frequency
Extremely low frequency in general language. Higher relative frequency in specific American technical fields (e.g., theatrical lighting, horticulture) than in equivalent UK fields.
Grammar
How to Use “foot-candle” in a Sentence
The [surface] requires [number] foot-candles.Measure the illuminance in foot-candles.The [light source] provides [number] foot-candles at [distance].Vocabulary
Collocations
Examples
Examples of “foot-candle” in a Sentence
adjective
British English
- The foot-candle measurement was taken at desk height.
- Refer to the foot-candle requirements in the appendix.
American English
- The foot-candle reading indicated insufficient light.
- We need a foot-candle meter for the audit.
Usage
Meaning in Context
Business
Rare. Might appear in specifications for lighting products in the US market or in facility management documents referencing old standards.
Academic
Used in historical contexts of photometry or in papers comparing measurement systems. Largely supplanted by 'lux' in modern scientific literature.
Everyday
Virtually never used.
Technical
Primary domain. Used in architecture (lighting design), photography (light metering legacy), horticulture (grow lights), and theatrical lighting in the US.
Watch out
Common Mistakes When Using “foot-candle”
- Using 'foot-candle' to describe the brightness of a light source itself (it measures light *received* by a surface).
- Pronouncing it as 'foot-candle' with equal stress; primary stress is on 'foot'.
- Misspelling as 'foot candle' (open compound) or 'footcandle' (solid); the standard is hyphenated.
FAQ
Frequently Asked Questions
No, it is an imperial (non-metric) unit of illuminance. The metric equivalent is the lux.
Primarily in older technical documents, some American lighting design fields (theatre, horticulture), or when dealing with legacy equipment and standards that use imperial measurements.
Multiply the number of foot-candles by approximately 10.764 to get the value in lux. For example, 10 fc ≈ 107.64 lux.
No, it is exclusively a noun (and can function attributively as an adjective, e.g., 'foot-candle meter'). There is no verbal form.
A unit of illuminance equal to the illumination produced by a uniform source of one candela on a surface one foot away.
Foot-candle is usually technical/specialized in register.
Foot-candle: in British English it is pronounced /ˈfʊt ˌkændl/, and in American English it is pronounced /ˈfʊt ˌkændl/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “Not applicable for this technical term.”
Learning
Memory Aids
Mnemonic
Imagine a single candle flame one foot away from a book—that's roughly one foot-candle of light on the page.
Conceptual Metaphor
MEASUREMENT IS A CONTAINER (e.g., 'The desk has 50 foot-candles of light'). LIGHT IS A FLUID (e.g., 'Foot-candles fall on the surface').
Practice
Quiz
What does 'foot-candle' measure?