Illumination Converter
Unit ConvertersConvert Lux, Foot-candles, and Phot with real-time EN 12464-1 workspace compliance auditing, cinematography EV calculations, and plant growth metrics.
Bi-Directional Photometric Omni-Grid
SI base unit: 1 Lumen / m²
Imperial standard: 1 Lumen / ft² (10.7639 lx)
CGS metric unit: 1 Lumen / cm² (10,000 lx)
Dynamic Spatial Room Illumination
2D real-time architectural cross-section reacting to illuminance levels (0 lx to 10,000+ lx)
Workspace Code Auditor
Dynamic compliance engine evaluated against EN 12464-1 & OSHA 1926.56 statutory regulations
Standard Office & Reading Requirements
Passes Standard Office & Reading Requirements (EN 12464-1 baseline: 500 lx). Recommended for writing, typing, CAD, and classrooms.
Photography Exposure (EV) Engine
Professional Cinematography & Camera Settings Estimator based on incident light lux value
Indoor Botany Matcher
Horticultural Plant Thriving Index & photosynthetically active radiation estimations
How to Use the Illuminance Converter
A step-by-step guide to converting photometric units, auditing workplace ergonomics, calculating camera exposure, and optimizing indoor plant growth.
Enter Illuminance in Any Photometric Unit
Type the light intensity into any field (Lux, Foot-candles, or Phot) or pick a real-world preset (e.g., Living Room 150 lx, Office Desk 500 lx, Direct Sunlight 100,000 lx).
Instant Real-Time Conversion
The tool instantly recalculates values across all optical metrics: 1 Foot-candle = 10.7639 Lux, 1 Phot = 10,000 Lux, plus Lumen/m², Kilolux, and Nox.
Observe Spatial Room Illumination Simulation
Watch the dynamic SVG interior adapt with realistic ambient cone lighting, lamp bulb glow coloration, and brightness perception.
Audit Workspace Compliance (EN 12464-1 / OSHA)
Check your illumination level against international occupational standards for office drafting, computer work, precision assembly, or surgical theaters.
Calculate Photography EV & Camera Exposure
For photography and film, select ISO (100â3200) and Shutter Speed (1/8000sâ1s) to compute Exposure Value (EV) and exact lens aperture f-stops.
Evaluate Indoor Plant PPFD & Daily Light Integral
Check estimated photosynthetic photon flux density (PPFD in ¾mol/m²¡s) and DLI to ensure optimal indoor plant and crop thriving.
Frequently Asked Questions (FAQ)
Expert answers regarding photometric units, inverse square law, workplace lighting norms, and photographic exposure values.
Q:What is the difference between Lux, Lumens, Foot-candles, and Candela?
Candela (cd) measures luminous intensity of the light source in a given direction. Lumen (lm) measures total luminous flux emitted in all directions. Lux (lx) measures illuminanceâthe density of luminous flux incident on a surface (1 Lux = 1 Lumen/m²). Foot-candle (fc) is the Imperial unit of illuminance (1 Foot-candle = 1 Lumen/ft² = 10.7639 Lux).
Q:What is the exact mathematical relationship between Lux and Foot-candles?
Lux = Foot-candles Ă 10.7639104. Conversely, Foot-candles = Lux / 10.7639104 â Lux Ă 0.092903. For a quick mental estimate, dividing Lux by 10 gives a close approximation (e.g., 500 lx â 46.5 fc).
Q:What is the Inverse Square Law of Illumination?
The illuminance E received on a perpendicular surface decreases inversely with the square of the distance d from a point light source: E = I / d², where I is luminous intensity in candelas. If you double your distance from a lamp (from 1m to 2m), the surface illuminance drops to one-quarter (25%) of its original value.
Q:What are the standard recommended illuminance levels (Lux) for indoor workspaces (EN 12464-1)?
Corridors and stairwells require 100â150 lx; living spaces 150â300 lx; standard computer desks, reading areas, and offices require 500 lx; technical drafting and architectural drawing require 750 lx; precision manufacturing and fine electronics require 1,000â1,500 lx; and surgical operating tables require 10,000â50,000 lx.
Q:How is Exposure Value (EV) in photography related to Lux?
At ISO 100 with a standard incident calibration constant (C â 250), illuminance E in lux relates to Exposure Value (EV) by: E = 2.5 Ă 2^EV, or EV = log2(E / 2.5). For example, bright office lighting of 500 lux corresponds to EV â 7.6, which matches camera settings such as f/2.8 at 1/60s (ISO 100).
Q:Why do indoor plants require PPFD and DLI instead of just measuring Lux?
Lux measures light weighted by the human eye's spectral sensitivity curve (photopic curve V(Îť), peaking in green at 555 nm). Plants do not use light the way human eyes see it; photosynthesis is powered primarily by blue (400â500 nm) and red (600â700 nm) photons within the Photosynthetically Active Radiation (PAR) band. PPFD (Âľmol/m²¡s) measures actual absorbed PAR photons, and Daily Light Integral (DLI, in mol/m²¡d) measures cumulative daily photosynthetic energy.
- E: Illuminance (Lux = Lumens / m²).
- ÎŚ (Phi): Total Luminous Flux (Lumens).
- A: Illuminated Surface Area (m²).
- I: Luminous Intensity (Candelas).
- d: Distance from the light source (m).
- θ (Theta): Angle of incidence of the light ray.
- EVâââ: Exposure Value at ISO 100.
Illumination Converter Table
| Unit | lux (lx) | kilolux | millilux | foot-candle (fc) |
|---|---|---|---|---|
| 1 lux (lx) | 1 | 0.001 | 1,000 | 0.0929031299 |
| 1 kilolux | 1,000 | 1 | 1,000,000 | 92.9031299064 |
| 1 millilux | 0.001 | 0.000001 | 1 | 0.0000929031 |
| 1 foot-candle (fc) | 10.7639 | 0.0107639 | 10,763.9 | 1 |
What is Illumination Converter?
Convert Lux, Foot-candles, and Phot with real-time EN 12464-1 workspace compliance auditing, cinematography EV calculations, and plant growth metrics. This photometric engine seamlessly bridges the gap between architectural compliance, artistic visual production, and indoor agriculture. The interface actively evaluates your lighting levels against strict occupational health standards to prevent eye strain. Simultaneously, it calculates the Photosynthetic Photon Flux Density equivalents to ensure your interior landscaping receives optimal biological energy.
Practical Calculation ExampleAn interior designer in Seattle is auditing a newly renovated open-plan office. They measure the desk surface lighting and input 500 into the BI-DIRECTIONAL PHOTOMETRIC OMNI-GRID under Lux. The WORKSPACE CODE AUDITOR immediately lights up green, confirming the area passes the Standard Office & Reading Requirements. Curious about adding greenery to the space, they glance at the INDOOR BOTANY MATCHER to verify that a Snake Plant will thrive perfectly at this light level. They click Copy Lighting Spec to attach the technical data to their final client handover document.
Reference Zones| Interface Element | Photometric Function | Practical Application |
|---|---|---|
| BI-DIRECTIONAL PHOTOMETRIC OMNI-GRID | Base Conversion | Translates raw illuminance between metric Lux, imperial Foot-candles, and scientific Phot. |
| WORKSPACE CODE AUDITOR | Regulatory Check | Verifies if the lighting meets strict legal standards for specific commercial tasks. |
| PHOTOGRAPHY EXPOSURE (EV) ENGINE | Camera Calibration | Computes the exact f-stop, ISO, and shutter speed needed for standard film and digital cameras. |
| INDOOR BOTANY MATCHER | Biological Viability | Recommends specific plant species that will survive under the current ambient light levels. |
History and Origin
The foundation of measuring illumination began with the "foot-candle," a highly literal unit standardized in the late 19th century based on the light cast by a single standard plumbing candle from one foot away. As the International System of Units gained global dominance, the Lux (lumens per square meter) replaced the foot-candle in scientific and commercial domains, though the imperial measurement remains fiercely guarded by the American film and lighting industries today.