My research group used to use a Hollywood spotlight to simulate the lighting in orbit. These lights take a long time to power cycle, so once they're on you kind of want to keep them on, otherwise it's 15-30 minutes once you turn them off before they fully power up again.
So we left it on. After one test we left it pointed at our test article, which was made of styrofoam. After a couple of minutes it started smoking and melting. If we hadn’t smelled the smoke I'm certain it would have caught on fire.
We made very sure we never left it pointed at a fire sprinkler after that.
A school I was working out rented out as a location. The lighting crew followed their standard protocols, power all lights with the generator so when the Location Manager orders the power down they know the lights are off. The wardrobe crew on the other hand decided to move one of the lights for their convenience and plugged it into the building power supply. Someone else had moved a garment rack into range of the light.
About 3am the fire alarm went off. One of the elderly nuns was sleeping in her room on the top level of the building, was carried out by a firefighter.
The school was a converted English Tutor Mansion, had a grand entrance with hand carved mahogany everywhere. The film company hired a crew of like 30 cleaners that were scrubbing the smoke out of the carvings with toothbrushes.
>We made very sure we never left it pointed at a fire sprinkler after that.
The one time we had an inadvertent discharge of a fire sprinkler in the historic building we're in was when a film crew had a light positioned too close to one. It was not close enough that someone without specific experience looking at it would have thought it was too close. The light wasn't even a high-powered outdoor film spotlight; it was for an indoor shoot. Film lights can just be very bright, and very hot.
I worked with a solar simulator that has 19 lamps, each using 35 kW of power. It has a heavy metal shutter that is used to quickly turn off the light. Once the shutter is closed, the operators have ~45 seconds to turn the lamp off, otherwise they risk damaging the shutter.
Some other facts:
* While handling lamps, you are not allowed to be in the lamp room without hearing protection, just in case one implodes.
* A single lamp emits enough light that it can cause permanent blindness.
* Lamps are water-cooled.
(it still lists the old power rating, but it was increased to 35 kW a few years ago, when BepiColombo was tested. The lamps were also refocused at that time, to cover a smaller diameter circle. The sun emits a ridiculous amount of light...)
I wrote the software that monitors lamp output during use, and also the software used to calibrate the alignment of the lamps (they need to be properly centered).
That article isn't as good (less technical/more 'pop' audience) but they both link the actual AAIB report which I found quite interesting and surprisingly readable, and I don't think either article has anything extra to offer. I'd suggest skipping straight to it:
https://assets.publishing.service.gov.uk/media/6544b3089e05f...
I just don't understand why all movie set lights haven't instantly been replaced by their LED equivalent. Why do people still use these things that are crazy expensive to run and can set things on fire?
Ever heard how painters hunt for pigments? Sure, if you run out of orange you can just mix red and yellow, but the end result will reflect different frequencies than when you used a dedicated orange pigment—meaning some oranges in your final work would look ever so slightly different (and sometimes very different under some light conditions or angles) from other oranges or from what you would like, especially over time.
The situation can also be flipped and apply to light sources, and those by definition are key in photography.
In case of LED light, its colour balance can be declared to match some reference Kelvin number, but because it is “fake”, a mix of spikes in the spectrum (roughly at R, G, and B for RGB LEDs, phosphorus-covered white LEDs have the spectrum more even but its own gaps and bumps), and materials of various colours can reflect inbetween those peaks, or right at those peaks, those materials can look 1) different from scene to scene and from light to light or 2) plain wrong in post production, compounding variance between camera sensors or films (which create colour from their own mix of R, G, and B), lenses, etc.
Added to other flaws of LEDs, such as longevity (of cheaper units), issues with brightness and colour reproduction consistency, PWM, etc., they make a poor choice for a variety of situations[0], but in photography particularly so, particularly where colour reproduction and continuity matter (TV and film).
By contrast, black body radiation—hot and more energy intensive—is a solid spectrum of even light, without spectral discontinuities or flicker at any brightness.
[0] In some situations those flaws are considered acceptable. You may have noticed how two identical OLED iPhones displayed at an Apple Store, even fully reset to defaults, can have obviously different white point when you look at them side by side—that’s colour reproduction/emission variance and/or degradation over time. Similarly, you can often spot PWM flicker if you reduce brightness and squint at an OLED phone with your peripheral vision. These things don’t matter much, since 99.99% of the time we look only at our own device and our colour perception and flicker tolerance is adjusted to it. Not so with photography; you can’t afford colour variance between two different lights even in cases where it’s not noticeable to the naked eye in the moment, whereas PWM restricts your FPS and shutter angle options.
The cost of running them isn't relevant. What is relevant: being able to get more light from a limited amount of house/set/generator power, and the control over them. They don't require a dimmer pack, just power and DMX (wired or wireless) to control their brightness, color temperature, activate special in-light effects like flickering/strobing, etc.
Some directors prefer the spectrum completeness and profile from tungsten (or the ultimate, carbon-arc, which is virtually indistinguishable from the sun.)
I also think there are levels of light that aren't really feasible except with carbon arc because LEDs don't like heat and that limits power density.
I don't remember what movie it was, but there's a photo of an enormous balloon light - larger than an entire house - over a farmhouse somewhere in the midwest, at night. Pretty sure it wasn't LEDs as the source, but I could be wrong.
Spectrum continuity and spikes, flicker, active cooling, ridiculously short lifespans at ridiculously high levels of brightness, and a sprinkling of “the old way is the only way”?
I've been on a couple of film sets and when those big lights are on you better not be caught unprepared especially not when they are focused. The lights are usually kept running between takes (and during shorter breaks) and you will definitely realize you are 'in the beam' when you walk across the set. Another commenter here mentions UV protection built into make-up, I wasn't aware of that but it makes good sense.
One thing I learned while webcasting Yves St. Laurent's fashion show in the mid 90's is that the flowers wilt within minutes of being placed due to all of the heat from the lights. So the way they dealt with that is that backstage there is an absolutely enormous amount of flowers ready to be deployed and they just cycle through flower arrangements continuously for the duration of the show so that the flowers are always fresh. It's tens of people walking to and fro without pause.
First, stage lighting is already uncomfortably hot for anyone working under them for any length of time.
Second, these weren't ordinary stage lights. These were lights for use outdoors to simulate natural sunlight, which is much brighter (and hotter) than what you'd normally use indoors.
Third, they were probably positioned too close, and left on for too long. Just a guess on this one.
There's a minimum distance of like 10-30ft with these lights. They're also uncomfortably warm, prompting humans to leave after a while but not airplanes.
I’ve explained this before but I’ll chime in here and explain it again. Spotlights like these used for filming get hot (temperature wise) as well as having the ability to focus the beam. The lights heat will fall off but a focused beam will retain more of its energy. Now, some movie makeup has built in SPF. Stage makeup definitely has some. On stage, you’ll often see fans blowing to keep people cool or they will use diffused lighting and not spotlights which don’t generate so much heat.
Spotlights like these though, you might as well be holding a giant magnifying glass. The beam is culminated and will cook whatever it’s pointing at. Will it cook a human? Yes if you stand there, still, for long enough. You will definitely get sun burned. If you get within 10 feet it will feel like your standing in an oven. Within 5 feet and your skin could boil.
So basically, this could have been a serious incident if they used a lower power light that did not cause the window to fail so obviously. I bet with a full pressure differential at cruising alt, this might have blown up catastrophically.
Quite scary what kinds of causes trigger such incidents. As a frequent flier, I would have never imagined something like this.
How are there no regulations that should have prevented or caught this? I bet there will be now.
Aircraft fuselages are not balloons, and they do not catastrophically pop if the fuselage is punctured in discrete locations. Relevant recommended viewing is "operation guillotine fuselage test" on YouTube, where large steel blades are dropped through pressurized aircraft fuselage sections to validate no explosive decompression. In the late 1950s, BTW.
Commercial aircraft are required to be designed to maintain 15,000 foot equivalent cabin altitude after any probable failure, which includes multiple missing windows, per the requirements of 14 CFR 25.841 and it's EASA equivalent.
There is already regulation in place that should have caught this but did not. The captain is required to perform an external visual inspection of the aircraft before departure, which follows a checklist that includes looking at the windows. It appears that did not happen.
> How are there no regulations that should have prevented or caught this? I bet there will be now.
I would think a pressure check would be trivial. I would also assume a visual inspection is part of takeoff (camera or human). I assume this sort of thing is rare enough to not warrant the extra time/cost of these trivialities.
* Damage to the left leading edge of the horizontal stabilizer was noted as well. Investigators found acrylic in the puncture, consistent with a window pane.
And:
* The aircraft remained properly pressurized throughout the flight.
Are not mutually incompatible? (i.e. a window pane hit the tail in flight and somehow the aircraft remained pressurized?)
There are three window panes on a commercial plane. The outside pane maintains pressure, while the middle one is a failsafe in the event the outside pane fails (the inner pane is cosmetic and to prevent people from messing with the important panes).
Without reading the report, the outside pane could have failed and hit the stabilizer while the middle pane continued to hold pressure as expected, therefore no contradiction in the two statements.
You need to pump air into a plane to provide oxygen. That implies that you need to let air out. The pressurisation system in planes is able to deal with a moderate amount of air exiting the aircraft without losing pressure, and the lower the altitude the easier that is.
As far as I understand it, there are several layers that make up an airplane window, the one in the middle is the vital one and the extra layers on either side have other purposes.
In this incident, the outer frame had melted and the outer pane had separated from the rest but the central layer was OK at that point in time.
Having so many of these huge lights, blasting out 12KWs each, for 4-5.5 hrs just to get a few photos of a plane sounds a little bit too much, but hey who am I to judge :-)
> more resistant to heat considering the distance they have from the engines, in case something went wrong
For the engine to melt a window, something has gone wrong enough that this tolerance isn't material. (You'd need a lot of heat. Plus enough turbulence to blow it laterally inward, but not so much that it's allowed to cool. That combination suggests a loss of power and a low-speed, i.e. low-altitude, stall.)
the engines don't put out a lot of radiant heat, especially at altitude where it is -50 outside. the lights on the other hand are putting out a metric fuck ton of heat directly at the illuminated area.
heat from an engine is directed straight out the back by nature of the turbines.
modern engines are also what are called "high bypass ratio" engines, where the outer ring of the engine (closest to the cladding) is really just air flowing by. the combustion area is smaller, in the center.
With an engine fire, at speed, the vast majority of the heat will be from the flame, in the air, traveling backwards at hundreds of miles per hour. This leaves the radiant heat. At speed, the radiant heat, from a fuel fire, has no hope of overcoming the many hundred mph wind that is scrubbing along the window, cooling it off.
I as thinking how hot it gets sitting on a tarmac in Saudi Arabia or Tucson in the summer. A nice BLACK painted fuselage seems like a really bad idea. Just a thought.
I was thinking this too... What if something caught fire in the aircraft during flight? I assume they land regardless but it goes from "Get the fire extinguisher and put it out" to "DO IT BEFORE THE WINDOWS MELT OFF!"
I'm a little surprised that the window panes aren't so much physically bigger than the opening such that even if the seal failed they'd still be held in place by cabin pressure.
[+] [-] GlenTheMachine|2 years ago|reply
So we left it on. After one test we left it pointed at our test article, which was made of styrofoam. After a couple of minutes it started smoking and melting. If we hadn’t smelled the smoke I'm certain it would have caught on fire.
We made very sure we never left it pointed at a fire sprinkler after that.
[+] [-] CodeWriter23|2 years ago|reply
About 3am the fire alarm went off. One of the elderly nuns was sleeping in her room on the top level of the building, was carried out by a firefighter.
The school was a converted English Tutor Mansion, had a grand entrance with hand carved mahogany everywhere. The film company hired a crew of like 30 cleaners that were scrubbing the smoke out of the carvings with toothbrushes.
[+] [-] cge|2 years ago|reply
The one time we had an inadvertent discharge of a fire sprinkler in the historic building we're in was when a film crew had a light positioned too close to one. It was not close enough that someone without specific experience looking at it would have thought it was too close. The light wasn't even a high-powered outdoor film spotlight; it was for an indoor shoot. Film lights can just be very bright, and very hot.
[+] [-] agent327|2 years ago|reply
Some other facts:
* While handling lamps, you are not allowed to be in the lamp room without hearing protection, just in case one implodes. * A single lamp emits enough light that it can cause permanent blindness. * Lamps are water-cooled.
Here's a picture of the back of the unit: https://www.esa.int/ESA_Multimedia/Images/2014/04/Sun_simula...
(it still lists the old power rating, but it was increased to 35 kW a few years ago, when BepiColombo was tested. The lamps were also refocused at that time, to cover a smaller diameter circle. The sun emits a ridiculous amount of light...)
Here's a picture of a spacecraft being lit up by the lamps (at a really low light level): https://www.esa.int/ESA_Multimedia/Images/2008/03/GOCE_ready...
I wrote the software that monitors lamp output during use, and also the software used to calibrate the alignment of the lamps (they need to be properly centered).
[+] [-] nashashmi|2 years ago|reply
>I’m really surprised lights used to simulate sunrise placed 20-30ft away could completely melt the foam holding the exterior windows in place.
https://news.ycombinator.com/item?id=38221699
[+] [-] ekianjo|2 years ago|reply
styrofoam melts super easily so not sure that says much
[+] [-] ibejoeb|2 years ago|reply
[+] [-] OJFord|2 years ago|reply
That article isn't as good (less technical/more 'pop' audience) but they both link the actual AAIB report which I found quite interesting and surprisingly readable, and I don't think either article has anything extra to offer. I'd suggest skipping straight to it: https://assets.publishing.service.gov.uk/media/6544b3089e05f...
[+] [-] davidhyde|2 years ago|reply
[+] [-] strogonoff|2 years ago|reply
The situation can also be flipped and apply to light sources, and those by definition are key in photography.
In case of LED light, its colour balance can be declared to match some reference Kelvin number, but because it is “fake”, a mix of spikes in the spectrum (roughly at R, G, and B for RGB LEDs, phosphorus-covered white LEDs have the spectrum more even but its own gaps and bumps), and materials of various colours can reflect inbetween those peaks, or right at those peaks, those materials can look 1) different from scene to scene and from light to light or 2) plain wrong in post production, compounding variance between camera sensors or films (which create colour from their own mix of R, G, and B), lenses, etc.
Added to other flaws of LEDs, such as longevity (of cheaper units), issues with brightness and colour reproduction consistency, PWM, etc., they make a poor choice for a variety of situations[0], but in photography particularly so, particularly where colour reproduction and continuity matter (TV and film).
By contrast, black body radiation—hot and more energy intensive—is a solid spectrum of even light, without spectral discontinuities or flicker at any brightness.
[0] In some situations those flaws are considered acceptable. You may have noticed how two identical OLED iPhones displayed at an Apple Store, even fully reset to defaults, can have obviously different white point when you look at them side by side—that’s colour reproduction/emission variance and/or degradation over time. Similarly, you can often spot PWM flicker if you reduce brightness and squint at an OLED phone with your peripheral vision. These things don’t matter much, since 99.99% of the time we look only at our own device and our colour perception and flicker tolerance is adjusted to it. Not so with photography; you can’t afford colour variance between two different lights even in cases where it’s not noticeable to the naked eye in the moment, whereas PWM restricts your FPS and shutter angle options.
[+] [-] KennyBlanken|2 years ago|reply
Some directors prefer the spectrum completeness and profile from tungsten (or the ultimate, carbon-arc, which is virtually indistinguishable from the sun.)
I also think there are levels of light that aren't really feasible except with carbon arc because LEDs don't like heat and that limits power density.
I don't remember what movie it was, but there's a photo of an enormous balloon light - larger than an entire house - over a farmhouse somewhere in the midwest, at night. Pretty sure it wasn't LEDs as the source, but I could be wrong.
[+] [-] ComputerGuru|2 years ago|reply
[+] [-] rtpg|2 years ago|reply
[+] [-] usefulcat|2 years ago|reply
[+] [-] Aardwolf|2 years ago|reply
[+] [-] unknown|2 years ago|reply
[deleted]
[+] [-] SkyPuncher|2 years ago|reply
[+] [-] gnabgib|2 years ago|reply
[0]: https://news.ycombinator.com/item?id=38221121
[+] [-] codedokode|2 years ago|reply
[+] [-] jacquesm|2 years ago|reply
One thing I learned while webcasting Yves St. Laurent's fashion show in the mid 90's is that the flowers wilt within minutes of being placed due to all of the heat from the lights. So the way they dealt with that is that backstage there is an absolutely enormous amount of flowers ready to be deployed and they just cycle through flower arrangements continuously for the duration of the show so that the flowers are always fresh. It's tens of people walking to and fro without pause.
[+] [-] tjohns|2 years ago|reply
Second, these weren't ordinary stage lights. These were lights for use outdoors to simulate natural sunlight, which is much brighter (and hotter) than what you'd normally use indoors.
Third, they were probably positioned too close, and left on for too long. Just a guess on this one.
[+] [-] buildbot|2 years ago|reply
[+] [-] hengheng|2 years ago|reply
[+] [-] reactordev|2 years ago|reply
Spotlights like these though, you might as well be holding a giant magnifying glass. The beam is culminated and will cook whatever it’s pointing at. Will it cook a human? Yes if you stand there, still, for long enough. You will definitely get sun burned. If you get within 10 feet it will feel like your standing in an oven. Within 5 feet and your skin could boil.
[+] [-] dmitrygr|2 years ago|reply
[+] [-] alexpotato|2 years ago|reply
The reasoning was that:
- college students are busy/forgetful so will leave the light on
- there are times of day where no one would be in a dorm room
- BUT that dorm room is a bigger dorm with potentially lots of other students
- an unattended halogen lamp could set fire to an object on a desk etc
this post feels like a much bigger version of the above
[+] [-] closeparen|2 years ago|reply
[+] [-] LASR|2 years ago|reply
Quite scary what kinds of causes trigger such incidents. As a frequent flier, I would have never imagined something like this.
How are there no regulations that should have prevented or caught this? I bet there will be now.
[+] [-] buildsjets|2 years ago|reply
Commercial aircraft are required to be designed to maintain 15,000 foot equivalent cabin altitude after any probable failure, which includes multiple missing windows, per the requirements of 14 CFR 25.841 and it's EASA equivalent.
There is already regulation in place that should have caught this but did not. The captain is required to perform an external visual inspection of the aircraft before departure, which follows a checklist that includes looking at the windows. It appears that did not happen.
[+] [-] nomel|2 years ago|reply
I would think a pressure check would be trivial. I would also assume a visual inspection is part of takeoff (camera or human). I assume this sort of thing is rare enough to not warrant the extra time/cost of these trivialities.
[+] [-] jacquesm|2 years ago|reply
[+] [-] gomox|2 years ago|reply
* Damage to the left leading edge of the horizontal stabilizer was noted as well. Investigators found acrylic in the puncture, consistent with a window pane.
And:
* The aircraft remained properly pressurized throughout the flight.
Are not mutually incompatible? (i.e. a window pane hit the tail in flight and somehow the aircraft remained pressurized?)
[+] [-] imadethis|2 years ago|reply
Without reading the report, the outside pane could have failed and hit the stabilizer while the middle pane continued to hold pressure as expected, therefore no contradiction in the two statements.
[+] [-] mjg59|2 years ago|reply
[+] [-] illwrks|2 years ago|reply
In this incident, the outer frame had melted and the outer pane had separated from the rest but the central layer was OK at that point in time.
https://thepointsguy.com/news/what-are-airplane-windows-made...
[+] [-] NKosmatos|2 years ago|reply
Having so many of these huge lights, blasting out 12KWs each, for 4-5.5 hrs just to get a few photos of a plane sounds a little bit too much, but hey who am I to judge :-)
[+] [-] juanse|2 years ago|reply
[+] [-] JumpCrisscross|2 years ago|reply
For the engine to melt a window, something has gone wrong enough that this tolerance isn't material. (You'd need a lot of heat. Plus enough turbulence to blow it laterally inward, but not so much that it's allowed to cool. That combination suggests a loss of power and a low-speed, i.e. low-altitude, stall.)
[+] [-] MadnessASAP|2 years ago|reply
[1] The complete list of options are typically starvation, suppression, evacuation. Apply in that order and do so quickly.
[+] [-] whalesalad|2 years ago|reply
heat from an engine is directed straight out the back by nature of the turbines.
modern engines are also what are called "high bypass ratio" engines, where the outer ring of the engine (closest to the cladding) is really just air flowing by. the combustion area is smaller, in the center.
[+] [-] nomel|2 years ago|reply
[+] [-] strangattractor|2 years ago|reply
[+] [-] kayfox|2 years ago|reply
The engines are under the wing, the windows are above the wing, they are not very close to the windows at all.
[+] [-] ssnistfajen|2 years ago|reply
[+] [-] SketchySeaBeast|2 years ago|reply
[+] [-] chankstein38|2 years ago|reply
[+] [-] userbinator|2 years ago|reply
[+] [-] ironmagma|2 years ago|reply
[+] [-] foota|2 years ago|reply
[+] [-] photoGrant|2 years ago|reply
The black-body radiation is the true heat coming from them