X

Imtra Learning Center

Betmun coin solana

Imtra’s Learning Center is a great resource for everything you need to know about your boat’s equipment and systems. Everything from product overviews, product comparisons, buying guides, troubleshooting guides, maintenance tips and more can be found here, and it’s always being updated. Be sure to also check out our video library for product demonstrations, how-tos, webinars and much more!

 

Imtra Learning Center

Measuring Light Output: Candela vs. Lumen

Measuring Light Output: Candela vs. Lumen

Author: Conrad Taylor/Friday, February 16, 2024/Categories: Lighting

Rate this article:
5.0

When it comes to determining the output, or brightness, of a light source, there are a few different ways to measure it, and each serves a specific purpose. Two of the most common units of measure for light output that you might see a lighting manufacturer use to describe the brightness of a fixture are candelas & lumens. While they both measure light output, they measure different aspects, and cannot be used interchangeably.

A lumen is the unit of measure for luminous flux, which is the total amount of visible light emitted from a light source in all directions. By contrast, candela is a unit of measure for luminous intensity, which measures the amount of light emitted in a particular direction. The reason the two units of measure cannot be compared, is because two lights with the same lumen output can have different candela values.

The relationship between candela, lumen, and the angle of light distribution is defined by the formula: Candela = Luminous Flux / Solid Angle. The solid angle represents the spread of light in three-dimensional space. Therefore, if two lights have the same lumen output but different solid angles (i.e., one concentrates light in a specific direction while the other disperses it more widely), they will have different candela outputs. In practical terms, this means that two lights with the same total brightness in lumens can appear different in terms of brightness when you consider how focused or spread out the light is.

Measuring Light Output: FAQs

What’s more important to know, candela or lumen?

When selecting lights for your boat and comparing options from different brands or models, it’s important to compare them using the correct unit of measure, and use the same unit for the comparisons. In general terms, candela is a better unit of measure to use for comparing task lights or directional lights, while lumen is a better unit of measure for comparing downlights or ambient light sources.

For example, when comparing two searchlights, using candelas will give you a better idea of how bright that focused beam will be, and at which distances, and the overall brightness of the light in all directions is rather useless information. On the other hand, when evaluating a dome light for the inside of a cabin or a utility light for an engine room, the overall luminous flux, measured in lumens, is a more important value to know.

In some cases you may want to know both values, like in an exterior deck light. Two deck lights could have the same lumen value, but if one focuses the beam in a 30° angle and the other has a 90° beam angle, they will have drastically different candela values. The 30° light will appear much brighter than the 90° light, but will cover much less area of the deck. So knowing both values can help you determine whether you’d rather use a brighter light that covers less deck area or a light that covers the whole deck but will appear less bright.

What’s the difference between raw lumens and fixture lumens?

One common discrepancy you might find between different brands and types of lights is that some may advertise their brightness using raw lumens while others use fixture lumens, so what’s the difference? Raw lumens refer to the theoretical output of a light source in a vacuum before accounting for any loss of light due to reflectors or lenses. Fixture lumens, on the other hand, are synonymous with luminous flux, or the total amount of light emitted from the fixture as perceived by the human eye. Therefore, fixture lumens are more important to know when evaluating the brightness of a light for your vessel.

Is candlepower the same as candela?

pexels-pixabay-27882...

Candela and candlepower are related concepts, but they are not exactly the same thing. Candlepower is an older term that was originally defined based on the light output of a standard candle, but is not commonly used today. Candela is the modern and standardized unit for luminous intensity within the International System of Units, as candela is defined based on the perceived brightness of light as perceived by the human eye, and it is not directly tied to the properties of an actual candle.

Conclusion

There are many different ways to measure the brightness of a light fixture, and different manufacturers use different units, so it’s important to know how to compare them. It’s often best to contact the manufacturers or dealers of the lights you’re evaluating to ensure you have all the relevant information to compare different lights. There are also many more factors to consider when picking out different lights beyond brightness, and Imtra can offer guidance on all of them. Be sure to check out all of our lighting articles here, or feel free to contact us with any questions you may have.

Print

Number of views (327)/Comments (0)

Please login or register to post comments.

Related Articles

What is Ingress Protection & Why Do IP Ratings Matter for Boating Equipment?

What is Ingress Protection & Why Do IP Ratings Matter for Boating Equipment?

An ingress protection (IP) rating indicates how well a device is protected against water and dust. Defined by the International Electrotechnical Commission (IEC), IP ratings provide a guideline to the degree of protection provided by mechanical casings and electrical enclosures against the intrusion of solids and liquids.  

Friday, October 20, 2023/Author: Conrad Taylor/Number of views (647)/Comments (0)/ Article rating: No rating
Categories: Lighting
How to Choose the Right Marine LED Lights for Your Boat

How to Choose the Right Marine LED Lights for Your Boat

There are seemingly endless options for LED lights on your boat, so how do you choose? In this article, we’ll explore the factors to consider when outfitting your boat with LED lights and how to choose the best ones to fit your needs.

Monday, June 20, 2022/Author: Conrad Taylor/Number of views (1277)/Comments (0)/ Article rating: 5.0
Categories: Lighting
Tips for Troubleshooting LED Lights on Boats

Tips for Troubleshooting LED Lights on Boats

Learn how to troubleshoot LED lights for boats and find solutions to other common LED lighting problems with these tips from Imtra’s Technical Support Engineer, Van Noorden.
Friday, August 14, 2020/Author: Conrad Taylor/Number of views (9027)/Comments (0)/ Article rating: No rating
 4 Factors to Consider when Choosing the Best Searchlight for Your Vessel

4 Factors to Consider when Choosing the Best Searchlight for Your Vessel

4 Key factors to consider so that you get the best searchlight for your vessel.
Friday, August 14, 2020/Author: Conrad Taylor/Number of views (4091)/Comments (0)/ Article rating: No rating
What to Consider When Choosing the Best Marine LED Lights

What to Consider When Choosing the Best Marine LED Lights

What should I consider when buying LED lights for my boat? Let’s take a closer look at the 17 most common questions people have before upgrading their lights.
Wednesday, March 18, 2020/Author: Conrad Taylor/Number of views (4782)/Comments (0)/ Article rating: No rating
Categories: Lighting
Den Haan Rotterdam Marine Navigation Lights

Den Haan Rotterdam Marine Navigation Lights

Based in Holland, Den Haan Rotterdam (DHR) has been manufacturing top-quality marine lighting products since the early 1920s. DHR started with tin oil-lamps that were used on ships, and have kept up with the latest technology for generations, now offering
Wednesday, March 18, 2020/Author: Conrad Taylor/Number of views (3445)/Comments (0)/ Article rating: No rating
RSS