Premium Membership ♕

CYBER WEEK OFFER 💥 Save 20% on PRO Membership Plan and Video Courses with the coupon CYM23 and learn from experienced engineers.

Home / Technical Articles / Basic parameters used in lighting you should know
Basic parameters used in lighting
Basic parameters used in lighting

Luminous flux

Luminous flux


The luminous flux describes the quantity of light emitted by a light source. The luminous efficiency  is the ratio of the luminous  flux to the electrical power consumed (lm/W). It is a measure of a lamp’s  economic efficiency.

Luminous intensity

Luminous intensity


The luminous intensity describes the quantity of light that is radiated in a particular direction. This is a useful measurement for directive lighting elements such as reflectors. It is represented by the luminous intensity distribution curve (LDC).




Illuminance describes the quantity of luminous flux falling on a surface. It decreases by the square of the distance (inverse square law). Relevant standards specify the required illuminance (e.g. EN 12464 “Lighting of indoor work-places”).

E(lx) = luminous flux (lm) / area (m2)




The luminance is the only basic lighting parameter that  is perceived by the eye. It specifies the brightness of  a surface and is essentially dependent on its reflectance (finish and colour).

SOURCE: Zumtobel Staff – The Lighting Book

Premium Membership

Get access to premium HV/MV/LV technical articles, electrical engineering guides, research studies and much more! It helps you to shape up your technical skills in your everyday life as an electrical engineer.
More Information

Edvard Csanyi

Electrical engineer, programmer and founder of EEP. Highly specialized for design of LV/MV switchgears and LV high power busbar trunking (<6300A) in power substations, commercial buildings and industry facilities. Professional in AutoCAD programming.


  1. Fahad
    Aug 28, 2017

    A really basic and helpful article. Thanks.

  2. Albert simiyu
    May 11, 2015

    explain the technology how the quantity of natural lights controls the quantity of illumination of the building?

  3. tabokhadra
    Sep 25, 2012

    you should add UGR AND GLARE

Leave a Comment

Tell us what you're thinking. We care about your opinion! Please keep in mind that comments are moderated and rel="nofollow" is in use. So, please do not use a spammy keyword or a domain as your name, or it will be deleted. Let's have a professional and meaningful conversation instead. Thanks for dropping by!

eighty seven  ⁄  87  =  

Learn How to Design Power Systems

Learn to design LV/MV/HV power systems through professional video courses. Lifetime access. Enjoy learning!

Subscribe to Weekly Newsletter

Subscribe to our Weekly Digest newsletter and receive free updates on new technical articles, video courses and guides (PDF).
EEP Academy Courses - A hand crafted cutting-edge electrical engineering knowledge