smoke

[Damian Vicente]

I need to shot a scene where a smoke cloud is needed. The scene is in an interior at some kind of party. The thing is that I need this cloud to be as compact as possible for a character to walk through and not be able to see.

 

I need some advice in order to make it.

 

thx

[Michael Nash]

An ordinary Halloween or Party fogger puts out a pretty dense cloud that dissipates fairly quickly. It just really depends on the scene and how exactly this cloud needs to look and materialize.

 

When you say "compact" do you mean contained to a small size, or dense (heavy)? To make a small, dense cloud of smoke show up as a solid object (and not just as haze) you would light it like any other three dimensional object. But thinner atmospheric smoke or haze shows up best when backlit and staged against a dark background.

[James Steven Beverly]

The secret to keeping a cloud of fog together is cold, still ambient air. Do the scene in a unheated studio in late fall or though winter with very little movement around the fog and the lights set back aways and it'll look great. I did some single handed, basic VHS tests for "The Black Sky" a while back for a scene where the entity first comes aboard the starship. The fog was to represent a ghostly presence, the well-known mists that often are accompany paranormal events and hauntings. It was late fall when I did the first tests and the fog just hung in the air for several minutes very slowly dissipating.

 

The lighting was just the set's ambient flashing disco lights and 1Ks, real simple, kinda dark and moody 3 point. The slowly billowing swirling fog that gently streamed out into bands and filament ribboned arms of fog caught in the shadowy light of the 1Ks and occasionally accented by the rear lit flash of a colored disco light gave me this beautiful but creepy look that was just what I imagined for the scene. It showed me I would be able to do what I wanted to do.

 

I also did some tests firing a laser pointer through some fog in a fish tank miniature set with a asteroid hung in front of a curved, hand painted starfield to see if I couldn't get more realistic looking laser fire in a scene where the damaged ship trapped in orbit around a mysterious planet that is surrounded by nebulous gasses and dust, coasts into an dense asteroid field and left with only minimal maneuvering power is forced to shoot it's way out. I used gelled light in greens and reds to light the fog this time.

 

The laser beam was visible in the fog and when it hit the potato shaped, dark, pitted rock I had found which looked VERY similar to actual asteroid pics from our own solar system that I had seen in my research, the effect was stunning, the rock seemed to glow red. If I had added a slowed down explosion, it would have been very effective, however, it was summer, which is very hot here in the desert and the fog, even in the tank, dissipated super quickly so in many instances during these informal tests, by the time I picked up the camera, framed the shot and aimed the laser, the fog had broken up into little patches in the tank and the beam was a broken line which although would have most likely been more realistic (A warship wouldn't want to have a direct line back to to it if it's firing on an enemy so the beam themselves would be designed to be as invisible as possible I would imagine) It just didn't have as dramatic an effect.

 

I tried the same effect of lighting fog with colored lights against a black wall after seeing a documentary on the making of Deep Blue Sea where they talked about how they had used luminescence keying to do the storm FX for the helicopter crash into the platform sequence. The shot the full sized helicopter on cables as the ran it into the full sized platform building with a pyro FX perfectly dry. They them added animated rotor blades and crashing swells the had taken from a rocky coastline in Carmel I believe, They them built a black box the same scale dimensions of the building with a black background and poured water over it in the guy's pool. They did this because they said it was very hard to get fine detailed water and smoke right with CGI, which is still true. They then luminescent keyed the black out and layered the water over the building. The scene in the movie looked great to me so I wanted to try and give my small, overworked animation staff a break and do as much with particle FX as possible practically and let them stick as much as possible to the larger smoke FX. I tested to see how fine of detail we could get in the smoke against a black background and it looked surprising good even on VHS.

 

I did another test where I placed a fog machine out of frame and set up an electric leaf blower right above it then pulled the main hatch doors open with fishing line while switching on the blower then the fog machine. the result was a fast moving stream of fog that rushed out though the slowly opening hatch which looked very cool and ominous When I get back to this project, all of these tests will prove to be invaluable.

 

For those of you that are wondering, I used VHS for these tests because at the time, my JVC GY-500 was a $6000 camera I had just bought and I didn't want to bang it up doing tests plus I was doing the tests by myself, very quickly without a lot a prep just as a feasibility study so the VHS camera I had was very light and expendable should I knock it over in my hast. I did do many of the later tests with the JVC. Of course, now, hen I do eventually shoot it, it'll be on 35mm or possibly HD because of all the CGI. We'll see. B)