I got restless last weekend and went to the Governor’s Ball at Citi Field in NYC mainly to see Big
Thief but Phoebe Bridgers played the next stage over right after Big Thief so I thought it would make a nice double bill and then I’d head out.
After the act before Big Thief, Pink Sweats, wrapped up (guess what, they all wore pink sweats) and the crowd cleared out I was able to get closer to the stage than I ever dreamed. I had to wait a while for Big Thief to set up and noticed all these gas cylinders between the subwoofers in front of the stage, then noticed more further back. What are they for? https://i.imgur.com/FXmZEEL.jpg
I suspect that’s your answer.
I couldn’t read the labels on the tanks, but they are probably acetylene. Which seems kind of dangerous, but does make huge balls of fire…
ETA: or maybe they are inert gas, used to pressurize some type of flammable liquid.
Here’s a super wild guess. Tanks with dark green shoulders indicate that they contain argon. Argon gas lasers are widely used for laser light shows. Where my connection is weak is that I have no idea if argon lasers of the kind they’d use need external pressurization or refilling.
Aye; I couldn’t quite make out the labels. Not sure why they were positioned between the subs and in front of the stage, tho; that seems like a precarious position. Those canisters aren’t anything I’d want attendees to be able to get their hands on easily.
I had some exposure to the industry 25 years ago and, even then, argon lasers were on the way out to make room for solid state YAG modules. They’re better in almost every way.
And, anyway, the argon stays in the laser tube, just like a neon lamp.
They did have a sturdy fence and several fit-looking fellows manning the space between the fence and the stage.
There were maybe 5 or 6 stacks of subs and batches of cylinders between the stacks, in addition to what was on stage. Whatever was in those cylinders there was a lot of it.
Aye; CO2 for a fog curtain was my first notion, but even then they are generally behind and under the stage so that techs can get to them in case of an emergency.
You’re right though, green normally indicates, if not argon specifically, another inert gas. Before I looked into it a bit ago after reading your comment, I’d have associated green with medical oxygen. It looks like there are different color codes for medical vs industrial or research cylinders but I can’t imagine needing either one in any significant quantity onstage.
Lasers (and relatedly, LEDs) have made incredible advancements in the last 30 years. DVD vs Bluray? Due to advancements in laser tech. Faster fiber optic? Similar advancements.
Here’s a full color system, turnkey for $2k: https://x-laser.com/products/lasercube-wifi-by-wicked-lasers-2-5w?_pos=1
It includes software and the entire projector system (which moves the beam and changed color and blanks as needed) which used to be tens of thousands at least if you were lucky.
What I think of is some crackhead in the first row rushing to the bottles and opening every valve and causing maybe too much pressure in, well, something. I don’t know much about stage tech, but wouldn’t that be a concern?
Almost all concerts use fog/smoke/mist, especially indoors. It used to be when everyone smoked, they didn’t need them, but after smoking was banned in most indoor places, they realized their lights didn’t quite look right anymore.
Usually but not always. If the audience is looking at where the beam terminates, fog or haze can be a distraction since they have to look through the visible beams to see the imagery on the screen or other surface. Often in these setups, the laser is the show. Like this for example:
But that’s not usually what entertainment lasers are going for. They’re usually performing beam effects where the bar of light moving through the air is the desired thing, frequently with other lighting.
You want the light to scatter and, like you said, particles in the air make that possible.