ALL ABOUT LED LIGHTS
Lighting plays a significant role in our modern lives, with nearly everything illuminated in one way or another. Every day, we encounter various types of electronic devices that emit or provide light, one of which is LEDs. LEDs, short for Light Emitting Diodes, are semiconductor devices that allow electrical current to flow in only one direction. With a wide range of LED lights available, we’d like to take a moment to share some insights and educate you about LEDs.
- How to Choose the Right Colour Temperature for the LED Light
- LED Corn Light Bulb Buyers Guide
- LED High Bay Lights Buyers Guide
- LED Flood Light Buyer’s Guide
- LED Stadium Lights Buyers Guide
TECHNICAL THINGS TO CONSIDER & GLOSSARY OF KEY TERMS
What are Lumens?
Lumens, or luminous flux, refer to the actual light output and are the most important factor to consider when purchasing LED lights. Determine how many lumens you need first, and then choose the wattage accordingly. Technically, luminous flux is the power or energy radiated per second in all directions from a light-emitting source. Its SI unit is the lumen (lm).
What is Lux (lx) or Foot Candle Power (Fc)?
Lux is the SI unit of luminous emittance and measures the luminous flux per unit area from a specific light source. Foot candle power is another unit used to measure the intensity of visible light but is not part of the International System of Units (SI).
What is Kelvin?
Kelvin, scientifically referred to as Correlated Colour Temperature (CCT), describes the colour appearance of light emitted by a source. It is measured in degrees Kelvin (K) and provides an indication of an LED’s hue rather than the amount of light. Common Kelvin values include:
- 2700K: Very warm colour with a strong brownish tint.
- 3000K: Warm white with a medium brownish tint.
- 4500K: Neutral or natural white—mostly white with a slight yellow tint to soften it. A good compromise for those who find 5000K too bright; ideal for office environments or UFO high bay lights.
- 6000K: A heavier blue tint, rarely used in standard lighting but suitable for car accent lighting.
What is Colour Rendering Index (CRI)?
CRI measures how accurately a light source renders colours compared to a reference source. Some lights are heavy in specific parts of the spectrum (e.g., 400–600 nm) and may not display colours accurately. CRI is rated on a scale from 0 to 100:
- Incandescent lights: Near-perfect score of 99.
- High-pressure sodium (HPS): Approximately 25.
- Metal halide: Around 50.
- Modern LEDs: Range from 70–95, with 70+ considered good, 80+ great, and 90+ excellent.
Note: CRI is being phased out in favour of R9, a metric that includes a fuller spectrum (600–800 nm) and provides a more accurate colour rendering. R9 is particularly relevant for applications requiring precise colour representation. For most LED fixtures, such as wall packs or parking lot lights, a CRI of 70+ is sufficient, while 80+ or higher is ideal.