Cinema Cemetery
The Life and Death of the Cloud Tank
Disclaimer:
The following is my own opinion and not the opinion of any studios I have worked for in the past or will work for in the future. All specific information comes courtesy of publicly accessible articles, please see the bibliography for more information.
In many effects-heavy films predating the 1970s, a fake sky would need to be a matte painting, a giant on-set painting, filmed smoke overlays or traditionally animated like a cartoon. Like any effects methods in film history, results ranged from terrible to amazing, but what none of them were able to capture, was a raw, natural sense of dynamic sky movement. It was missing a key element, organic chaos.
The cloud tank “...is an effect and process first developed by special effects artist Douglas Trumbull during his work on Steven Spielberg’s 1977 film Close Encounters of the Third Kind. (1)”
Throughout the course of the film, the sky is almost a character. It’s reactive, shifting, and interacts with various elements such as the alien’s spaceship. In terms of the actual details pertaining to the way the vfx team pulled it off for Close Encounters, ”Scott Squires was responsible for thinking up the specific setup used on that film. (4)”
At Hungry Creature Productions, we actually have a detailed video on how you can create similar effects at home, but for those who haven’t seen that video here’s a very brief rundown on what is involved in the execution of this practical effect.
“The basics are a large all glass aquarium was filled halfway with salt water and then fresh water was carefully added to the top. Salt water is heavier so tends to stay on the bottom….you want to avoid mixing them if possible. (2)”
“Next white liquid tempra paint is injected in the fresh water portion (top), usually just a few inches from the dividing line of the fresh and salt water...when the tempra paint is injected it billows outward like cumulus clouds and will tend to sink a bit. But the salt water prevents it from going lower so the 'cloud' tends to flatten it's base on the salt water line and billow outward, similar to real clouds based on air pressure levels. (2)”
“To create the different effects, he (used) a combination of food colorings, condensed milk, sprinkles, and glitter. (3)”
The water tank
“...as used on Close Encounters (was a) 2000 gallon glass tank approx 7 x 7 x 4 feet deep (2)”
But you can do a smaller scale version of the effect in a regular sized fish tank.
“This process is described as laborious; Trumbull and his team only managed to shoot one Cloud Tank effect per day, maybe two if they were lucky. (1)”
Yet the results are amazing! Depending on the method they can look believably realistic or creepily alien in nature.
“The success of Cloud Tank effects as an atmospheric quality in Close Encounters of Third Kind inspired Steven Spielberg and other filmmakers to continue utilizing the effect for intense, climactic and dramatic scenes in Raiders of the Lost Ark (Spielberg, 1981), Poltergeist (Hooper, 1982), and Independence Day (Emmerich, 1996). Although Independence Day used this technique, it was manipulated by computer technology (1)”
“These (resulting) cloud elements would then be combined with live-action footage, or model photography, to produce a really cool, very organic looking shot.
Here at Hungry Creature, we’ve used this method in several places during the creation of our short film, Senescent!
The problem with using this technique, however, is that you're never really sure what you're going to get, and it's impossible to control precisely what happens. Basically you just have to keep shooting, and hope to catch something cool on film. (4)”
And here we’ve struck upon the Achilles heel of the cloud tank as a practical effect. The film industry is not particularly interested in something it cannot fully control, quantify, direct, and bill for. The artistry of the cloud tank technique has so many factors: composition of the milk-liquid, temperature of the water, placement of the camera, the evolution of shape, etc, that are uncontrollable. This is the beauty and downfall of the technique. You could work hard with the tank for an entire day and still end up with something completely unusable, or you could get everything you needed for the week in a single day.
“Like most practical effects, the pure joy of experimenting with Cloud Tanks is something a computer cannot match or take away. (1)”
You’ll never get something so organically random from a computer, though you WILL get something far more directable from a computer simulation. At the end of the day, cloud tanks were “...a great way of creating organic shapes, which would otherwise have (had) to be done with hand-drawn animation or perhaps smoke. (4)”
But the film industry is a game of numbers and control, if it cannot fit in a spreadsheet or be reworked daily as per client nitpicks, then Hollywood has no interest in it. Movies are, after all, all about money. Anyone who tells you otherwise has their head in the clouds.
This has been cinema cemetery, digging six feet deeper into film-making culture.
-Josh Evans