One of the most enchanting visual effects techniques from the pre-digital age were cloud tanks. Any dramatic, swirling sky (like this image from Close Encounters) was created this way. I remember my father shooting them for many features. Watching miniatures being shot was always fascinating but the clouds unpredictable majesty made them very special.
My father would build a massive fish tank, hundreds of gallons; deep, more of a square than a rectangle. The glass would be distortion-free, museum glass. After the laborious task of cleaning and re-cleaning to ensure no dust was left in the tank, it would filled with filtrated water (obviously any particles, however small would catch the light). Once filled, set against black drape, camera positioned at a low angle, looking up at the underside of the surface; accurately creating the dramatic lighting and perspective of the shot that it would be composited into. Turning over at 50-100fps, white or grey paint (it could even be milk or cream) would be carefully poured into the water. Undulating near the surface the liquid would be swirled by a stick or pushed by a jet of water. It was wonderfully random, there was a refined talent to "puppeteering" the clouds; interpreting the dramatic brief, keeping it on the edge of visual reality (the coming of Gozer from Ghostbusters, below). Within 30 seconds it was all over, the paint would dissipate, the clouds ephemeral curvaceousness was replaced by a big tank of milky water...the long laborious process of re-setting would begin.
The artist Kim Keever creates and photographs marvellous water tank dioramas. Initially you are caught by their painterly landscape qualities, reminiscent of Romanticism or the Hudson School, an evolution of the tradition but of dreamlike primordial world. In close the rocks and trees reveal a primitive, subversive quality, a conceptual artifice.
We feel the grime on the glass, the inaccuracy of scale, the liquid filing the vista. Unlike the immersive quality of film effects, Keever reveals a miniature world that we recognise but know could never exist. They beautifully convey the transience, randomness of nature and creation...the fleeting wonder of the cloud tank.