Smoke trailing off an actor

[Andre LeBlanc]

Hello all,

 

I need to do an effect where it looks like smoke is trailing off my actor. He'd be fully clothed, but as he moves he'd be leaving a trail of smoke behind him. His range of movement wouldn't be too far-- possibly 6 or 7 feet, and in the shot you'd probably see him from the knees up. I tried a test using a fogger, but it was tough to control... even with flexible tubing directing the smoke. Also, the smoke doesn't need to look like it's shooting off of him (the fogger effect), mostly just trailing.

 

Anyone ever seen this type of effect done before practically? I'm sure I've seen it in other movies. I just can't remember which ones. Any info is greatly appreciated!

[Lee Maisel]

If you put an insulator between the actor's back and their shirt, you can soak the back with compressed "air dusters" held upside-down.

This, combined with their body heat will create quite a bit of vapor that looks like smoke coming off of them.

[Douglas Sunlin]

Here's what I would do.

 

If you get an overheated person (say they've been in a sauna), wet their skin and put them in cold weather, steam will rise off their skin. Now get your actor in a green suit and a green screen, with backlighting and with sauna et al., so all you have visible (after processing) is the steam.

 

Superimpose this over your original scene and you're good to go.

Edited September 19, 2007 by Douglas Sunlin

[Brian Dzyak]

I can't remember which Indiana Jones movie it was offhand, but there is a shot of Harrison Ford running away from something and there is a "cloud" of dust or smoke trailing behind him. It was in the first (Raiders) or the third (Crusade). They probably coated his leather jacket with Fuller's Earth (sp?) and let it fly off naturally.

 

You could try something like that ... maybe use baby powder (white) and backlight it. If the shot is short enough in length, it might sell as smoke.

 

 

Good luck!

[Andre LeBlanc]

Oh yes! I think it was Temple of Doom, after Jones stops the mining crate on its tracks by putting his feet on the tracks to slow it down. I'll look it up. Using some form of powder sounds like a good test to try.

 

In terms of shooting the smoke, and then comping it in post, it's a tricky in this case, because it's a hero effect, and our character will be right in the foreground. I also considered doing all the smoke in post, but for such a close-up shot, it's better to spend the time to figure out a practical solution. It will just work better.

 

In terms of the compressed air solution, that sounds interesting. I've never tried that. Isn't it freon that leaks out when you turn the can upside down?

Edited September 19, 2007 by Andre LeBlanc

[Daniel Sheehy]

Isn't it freon that leaks out when you turn the can upside down?

It is the propellant in liquid form. Probably not one of the Freons, which is a trademark of DuPont's.

It probably contains difluoroethane, trifluoroethane, or tetrafluoroethane.

Edited September 20, 2007 by Daniel Sheehy

[Lee Maisel]

It is the propellant in liquid form. Probably not one of the Freons, which is a trademark of DuPont's.

It probably contains difluoroethane, trifluoroethane, or tetrafluoroethane.

 

 

Correct: and it seems to last pretty long if you soak it good. The warmer it is, the more vapor there is.

[Daniel Sheehy]

...The warmer it is, the more vapor there is.

Be careful around the vapours... they are not meant to inhaled.