How Bright is 7 Watts? Understand Lighting and Brightness
Doing some research – specifically keyword research – I came across this question – How bright is 7 watts? This made me sit back and think. If people are asking how bright 7 Watts is, then you could put any arbitrary wattage in the place of 7 and the question could be asked in an infinite number of ways. But the explanation can also be done in just as many ways. Instead, here I wanted to cover some ways to look at this for someone who is working on trying to answer this question.
This all depends and depends on so many different factors. A watt is a measurement of energy; therefore, 7 Watts of what? LED? Compact Fluorescent? This number has no real meaning to it other than how much energy the lamp (or device) will require per hour.
Instead, we need to look at the lumen output. This also varies between manufacturers and is a better indicator as to how “bright” a light will be. In many different technologies, most of the wattage is wasted as heat and there really isn’t much wattage attributed to brightness.
Another thing to look at is distribution, specifically with LEDs. A wide distribution pattern on a flood will throw light in a larger area and spread it out further than a narrow distribution pattern. Distribution patterns change the way the light bends out from the source. Learn more about the various distribution patterns by checking out What You Need To Know About Light Distribution Patterns.
Finally, look at the color temperature of the light source. Is it 2700K which is a more orange / amber color, or 6000K which is closer to sunlight and has a much higher blue spectrum? This also can play into the brightness factor. Lower numbers make it harder to see differences and are more of a strain on the eyes and higher numbers make it much easier to see even the slightest of differences because it is closer to sunlight. There are pros and cons to both ends of the spectrum, so knowing what task needs to be performed will allow you to make the decision.
So next time the question arises of how bright a ? Watt light is, instead ask what the light output is, Lumen per Watt efficiencies, color, etc. This will help you better understand the actual brightness of a specific lamp.