Does Combining Lumens Make a Difference?

  • Thread starter mattloto
  • Start date
In summary, the conversation discusses the relationship between light bulbs and lumens, as well as how to measure the brightness of a light source. The participants also touch on the importance of understanding units of visible radiation and how they affect communication with others. Ultimately, it is concluded that lumens do add together, but the spectral output of the light source must also be taken into account when converting watts to lumens.
  • #1
mattloto
1
0
I've looked for this answer around the web, and I've gotten mixed results, so I'm asking here. If I have 2 light bulbs that produce 1k lumens each, will it be the same as 1 light bulb producing 2k lumens?

And on the topic, if I have a light source and I put a lens between it and a wall, what measurement will tell me how bright the image will be when it hits the wall. Thanks!
 
Physics news on Phys.org
  • #2
I believe that they do add with each other.
 
  • #3
mattloto, get yourself educated in the units of visible radiation. Actually, there are a lot of them, some derived, like the lumen. Once you have the definitions down correctly you can always communicate with others accurately. You might start here:
http://en.wikipedia.org/wiki/Lumen_(unit )
 
Last edited by a moderator:
  • #4
Lumens are a photometric version of radiant flux, the radiometric units are Watts. Because flux (power) is an integrated quantity, it does not have any directional dependence. So yes, the lumens will add.

However, because 'lumens' takes into account the spectral sensitivity of vision, you have to be careful when converting watts to lumens- two identical wattage bulbs, if the spectral output is different, will have different lumens.
 
  • #5


I can say that combining lumens does make a difference. Lumens are a measure of the total amount of visible light emitted by a light source. Therefore, if you have two light bulbs producing 1k lumens each, the total amount of light emitted would be 2k lumens. However, the distribution and intensity of light may differ between using two bulbs versus one bulb producing 2k lumens. This could affect the overall brightness and quality of the light.

In regards to the second question, the measurement that would determine the brightness of the image on the wall would be the illuminance, measured in lux. This takes into account the distance between the light source, lens, and wall, as well as the intensity of the light. Other factors such as the lens' focal length and the size of the light source also play a role in determining the brightness of the image.
 

FAQ: Does Combining Lumens Make a Difference?

What are lumens and how are they measured?

Lumens are a unit of measurement for the total amount of visible light emitted by a source. They are calculated by measuring the amount of light that falls on a surface, also known as illuminance, and multiplying it by the area of that surface. This measurement is commonly used to describe the brightness of light bulbs and other light sources.

How do lumens impact the brightness of a light source?

The more lumens a light source has, the brighter it will appear. For example, a 100-watt incandescent light bulb typically produces around 1600 lumens, while a 60-watt equivalent LED bulb can produce the same amount of light with only 800 lumens. This means that a higher lumen count does not necessarily mean a higher wattage or energy usage.

Does combining lumens from multiple light sources increase the overall brightness?

Yes, combining lumens from multiple light sources will increase the overall brightness. This is because the total amount of light emitted is the sum of all the individual lumens. However, the distribution of light may vary depending on the arrangement and direction of the light sources.

Is there a maximum limit to the number of lumens that can be combined?

Technically, there is no limit to the number of lumens that can be combined. However, practical limitations such as the space available, the power supply, and the desired level of brightness may affect the feasibility of combining a large number of lumens. It is important to consider safety precautions and not exceed the recommended wattage for a specific light fixture.

What other factors should be considered when combining lumens?

In addition to the total number of lumens, it is important to consider the color temperature, color rendering index (CRI), and beam angle of the light sources. These factors can impact the perceived brightness and quality of light. It is also important to consider the purpose and location of the lighting, as different settings may require different levels of brightness and color.

Similar threads

I Lux-meter, candelas or lux, measuring nits in practice
Replies
2
Views
4K
Converting Candelas to Lumens for Car Headlights
Replies
12
Views
4K
Determining the brightness on a projected surface
Replies
2
Views
2K
Burnout of 6300 Lumen Light Bulb: Why?
2
Replies
52
Views
5K
I Why does my ceiling glow in the dark?
Replies
12
Views
2K
What Are the Differences Between Nits, Lumen, Lux, and Candela?
Replies
13
Views
42K
I Help Understanding Luminance Calculation Process
Replies
1
Views
1K
I Can reflected light be used to create an accurate spectrometer?
Replies
14
Views
2K
B Can someone explain this projection distortion effect
Replies
5
Views
2K
Radiometric and Photometric units
Replies
4
Views
14K

Hot Threads

Recent Insights

Back
Top