Originally published at: http://boingboing.net/2016/10/19/bright-lights-big-drones-new.html
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Maybe it’s me being irrational but measuring light in watts bothers the heck out of me. It’s a meaningless measure and we have actual scales we can use to measure light like lumens and candles and such.
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UFO sightings are going to up 1000%
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Well, for battery-powered devices like these, watts is an incredibly important measure.
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It’s pretty clear to me they are using it as a measure of brightness and not operating time.
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Agreed, but in the world of solid-state lighting, Watts make a lot of sense. You want to be able to quantify efficiency (electrical power in vs light power out). Also, we measure light power (irradiance) with electrical instruments that read out in Watts, so translating that to lumens introduces an extra step and some possible error.
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If LED bulb A outputs 30 lumen @ 5 watts and LED bulb B outputs 80 lumen @ 5 watts, how can a watt be considered useful? Different bulb types and even the same type from different manufacturers have different lumen output per watt.
It’s my understanding that the watt/lumen conversions are intended for the standard incandescent bulb.
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A lumen is a candela*steradian, and a candela is 1/683 watts per steradian. So, there’s a direct relationship between watts and lumens. I think lumens per watt has to do with energy efficiency, but I’m not sure.
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Or down 100%. When drones became popular, it seemed to me that UFO sightings must have really had the wind taken out of their sails.
“What’s that weird light up in the sk-”
“Drone?”
“Oh… yeah, probably.”
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You also need to know how the light is being cast - isotropic or focused spot.
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Huh, I thought the watt there was the measure radiant energy which is converted into luminous energy and not a measure of joules per second consumed by the diode on the electronic circuit.
Lumens per watt is called the efficacy and it is entirely about how efficiently the source uses the watts to make lumens.
Lumens are a direct measurement of how much light is created by the source, a measure of the luminance.
Foot candles are a measurement of how much light hits something from a certain distance from the source, a measure of illuminance.
They are all related and useful, but each one is only going to tell a portion of the story, as @anon29631895 also makes mention of how those lumens are used once they are created. You can have two sources with the exact same lumens and wattage but result in a very different measurement of foot candles ten feet away.
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Which is why the secret Alien forces have pushed drones onto the market place.
This is great cover for the impending invasion force.
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How does he rig the copter to fog at 1:30? Seems like a substantial addition to the load.
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There was a decline in ghost sightings after the popularization of cell and smart phones. I always thought that was because the feeling of connectedness granted by the phone made people less likely to feel creeped out and imagine seeing things, and having a camera at all times deflates claims of sightings. But I think it’s clear what’s really going on - cell phones are actually powered by ghosts.
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We tend to keep everything in Watts. For instance, 5 Watts powering the device yields 500 mWatts total light output means the device is 10% efficient at converting electrical power to light. We also evaluate irradiance (W/cm2) and fluence (J/cm2) as important metrics.
I used to have a 1000w LED light with a 72w power adapter. The problem with measuring LEDs in watts is that unlike incandescents, there is a wide range of efficiency.
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