How to read a candlepower illumination curve

I’ve come across this a few times and I have no clue how to read this curve from MEEB. How do I read this?

@coachbryanhoward @coachmarkbailey


Great question and thank you for remembering to post this to the PPD community. These types of graphs show up on fixture cut sheets and are used to help designers understand the light levels that are produced by the fixture. The angles along the right and bottom of the diagram indicate the angle from the center of the fixture. The curved lines indicate the light levels. So let’s say the fixture is flush with the ceiling, 90-degrees represents the ceiling plane and this fixture doesn’t create any light on the ceiling plane. 0-degrees is directly below the fixture which is where the greatest light is created.

Here are some good websites to help understand these graphs and how they might look different for down-lights, wall sconces, and other types of fixtures:

6300 N. Northwest Highway P.O. Box 31846, Chicago, IL 60631-9998 / All rights reserved © 2020 Black Spectacles.