Lux (lux) Converter

What is Illuminance?

Illuminance is a measure of the amount of light that falls on a surface. It is typically measured in lux, which quantifies the light intensity per unit area. A higher illuminance means a brighter surface.

What are the common illuminance units?

• Lux (lx): The SI unit of illuminance, representing one lumen per square meter.
• Foot-candle (fc): A non-SI unit often used in the United States, where 1 fc = 10.764 lux.

What is the difference between illuminance and luminance?

Illuminance measures the amount of light falling on a surface, while luminance refers to the brightness perceived by the human eye from a surface. Luminance is affected by the light source and surface properties.

What are some examples of illuminance values?

• Moonlight: ~0.1 lux
• Streetlight: ~5-20 lux
• Indoor lighting: ~100-500 lux
• Direct sunlight: ~10,000-100,000 lux

How does illuminance affect human perception?

Illuminance plays a major role in how we perceive the brightness of our surroundings. Higher illuminance leads to a brighter environment, making it easier to see and perform tasks, while low illuminance can lead to eyestrain or difficulty seeing.

Why is illuminance important in building design?

• Lighting design: Proper illuminance ensures that spaces are lit effectively for tasks, comfort, and aesthetics.
• Energy efficiency: Balancing natural and artificial light helps reduce energy consumption.
• Health and well-being: Proper lighting impacts mood, productivity, and overall well-being.

How do you convert between illuminance units?

To convert between lux and foot-candles, use the following formula:1 fc = 10.764 lux. Use this conversion to switch between these units based on your needs.

How does time of day affect illuminance?

Illuminance varies significantly depending on the time of day, with higher values during the day due to natural sunlight and lower values at night. For example, outdoor illuminance can reach over 100,000 lux in direct sunlight but drops to less than 1 lux during the night.

What is the recommended illuminance for various tasks?

• Reading or studying: ~300-500 lux
• Office work: ~500-1000 lux
• Gymnasium or warehouse: ~100-300 lux

How does weather affect outdoor illuminance?

Cloud cover, rain, and other weather conditions can decrease outdoor illuminance by blocking sunlight. On overcast days, the illuminance can be as low as 1,000-5,000 lux, compared to 100,000 lux in clear, direct sunlight.

Can illuminance be measured indoors?

Yes, illuminance can be easily measured indoors using a light meter. This helps assess the effectiveness of indoor lighting and ensure that the lighting meets the requirements for different tasks or spaces.

What is the relationship between illuminance and light intensity?

While light intensity refers to the amount of light emitted from a source, illuminance measures how much light reaches a surface. A brighter light source can lead to higher illuminance, depending on the distance and angle.

How do you measure illuminance?

• Light meter: A device used to measure illuminance, typically in lux or foot-candles.
• Photodetector: A sensor that detects the intensity of light, often used in scientific measurements.
• Smartphone apps: Some smartphones have built-in sensors that can estimate illuminance.

What is the illuminance of a typical lightbulb?

The illuminance from a standard lightbulb depends on its wattage and the distance from the light source. A 60-watt incandescent bulb typically produces around 800 lumens, which translates to about 80 lux at a distance of 1 meter.

How does illuminance affect photography?

In photography, the correct illuminance is essential for proper exposure. Higher illuminance means you can use faster shutter speeds or smaller apertures, while lower illuminance requires slower shutter speeds or larger apertures to capture enough light.