In this new presentation, I dive deeper into key factors that influence lighting performance and visual comfort: 💡 Color Rendering Index (CRI) – How lighting affects color accuracy 💡 How CRI Affects Different Environments – The role of CRI in various settings 💡 Correlated Color Temperature (CCT) – Choosing the right CCT for different applications 💡 MacAdam Steps – Understanding color consistency in lighting 💡 Unified Glare Rating (UGR) – Managing glare for visual comfort 💡 Recommended UGR Levels – Best practices for different environments.

1. Lighting Quality
A Deep Dive into Color Accuracy, Consistency, and Visual Comfort
Presented by Mina Anis

2. Agenda
1.Introduction
2.Color Rendering Index (CRI)
3.How CRI Affects Different Environments
4.Correlated Colour Temperature (CCT)
5.Choosing the Right CCT for Applications
6.Macadam Steps
7.Unified Glare Rating (UGR)
8.Recommended UGR Levels
9.Summary

3. Back to Agenda
Introduction
• Lighting quality affects how we see colors, perceive
brightness, and experience comfort.
• This presentation covers Color Rendering Index
(CRI), Correlated Color Temperature (CCT),
Macadam Steps, and Unified Glare Rating (UGR).

4. Real-World Example:
• Retail stores use high CRI lighting (90+) to make products
look more vibrant.
• Office lighting with low CRI can make colors appear dull and
unnatural.
What is CRI?
• A measurement (0–100) of how accurately a light source
reveals colors compared to natural sunlight.
• Higher CRI = Better color accuracy.
Color Rendering
Index (CRI)
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5. Back to Agenda

6. CRI Rating Lighting Quality Common Applications
90-100 (Excellent) Very accurate color rendering Art galleries, photography, medical lighting
80-89 (Good) Near-natural color appearance Offices, classrooms, retail stores
60-79 (Average) Moderate color distortion Streetlights, warehouses
Below 60 (Poor) Colors appear unnatural Industrial and outdoor lighting
How CRI Affects Different
Environments
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7. Correlated Color
Temperature (CCT)
• Measured in Kelvin (K), CCT defines
whether a light source appears warm,
neutral, or cool.
• Lower CCT = Warm tones (yellowish light)
• Higher CCT = Cool tones (bluish light)
What is CCT?
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8. CCT (Kelvin) Lighting Appearance Best Applications
2700K - 3000K Warm, cozy Homes, hotels, restaurants
3500K - 4000K Neutral white Offices, classrooms, retail stores
5000K - 6500K Cool, daylight-like Hospitals, factories, outdoor lighting
Choosing the Right CCT for
Applications
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9. Macadam Steps
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10. Back to Agenda
• A measurement of color uniformity in LED
lighting.
• The fewer Macadam steps, the more
consistent the light color.
• LED manufacturers aim for 3-step or 5-
step Macadam ellipses to ensure minimal
color variation.
What are Macadam Steps?
Macadam Steps

11. Back to Agenda
• Inconsistent lighting can cause visible
differences in color between fixtures.
• Essential for high-end retail, museums,
and architectural lighting.
• Lower Macadam steps = Better color
consistency.
Why do Macadam steps matter?
Macadam Steps

12. Unified Glare
Rating (UGR)
• A measurement (range: 10-30) of how
much glare a light source produces.
• Lower UGR = less glare & better visual
comfort.
What is UGR?
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13. UGR Value Glare Level Best Applications
≤10 No glare High-end offices, art galleries
13-16 Comfortable lighting Offices, libraries, retail
19-22 Moderate glare Classrooms, general lighting
>25 High glare (uncomfortable) Warehouses, floodlights
Recommended
UGR Levels
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14. Summary
• CRI ensures true colour rendering.
• CCT determines the warmth or coolness of light.
• Macadam Steps ensure colour consistency.
• UGR measures glare and visual comfort.
Choosing the right CRI, CCT, and glare control ensures
a visually comfortable and efficient lighting
environment.
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