Understanding lighting fundamentals is critical to successful lighting design.
Here are the key lighting terms and concepts:
• Efficacy – Energy shown in lumens per watt (lpw)
• Lumen – Intl Measurement for visible, spherical light – more accurate than watts.
• LPW – Lumens per watt- Lumens output divided by consumed watts
• Foot Candles – Measures light on a surface
• Foot Candle – One foot candle equals one lumen per sq. foot
• Candle Power – Measure light in a specific direction
• Lux – European – Shown as 10x Foot Candle
• Kelvin Temperatures – Colors of the spectrum
• Watts – Measures heat; not light output
• Lumen Maintenance/ Dep. – the degree in which LPW is maintained
• CRI – Color Rendering Index (1-100). Intl for light quality
• Lamp Delineation – MR, R, PAR, A, E12, E27, T, G and GU
• Watts to Lumens – Approx. 10-14 x factor (avg.)