Cold F/X : dry ice or fog machine ?

[Joe999]

I need to do a short film, indoors, very simple set up (white backdrop, actors in chair) and I want to give the illusion of the actor being a cold environment. I would like to create the effect of mist such as from ice. Any thoughts on if I should try to do this with dry ice, or a fog machine, or software f/x? I am concerned somewhat about the fog machine-- the same room has my computer in it although I suppose I could shround that in plastic to protect it somewhat. Dry ice is not the easiest thing to locate but I think I could get hole of some (just called a dry ice supplier in my town but no only bots answered--beware the robots taking over the world!).

Additional Q: If I go with a fog machine, what wattage to get? I could also see using a fog machine for a horror short if I could somehow power it off a car DC cigarette lighter or car battery--could actually be fun for a horror short in the woods or cemetery. But for the current short film project (my first!) I definitely need to do whatever will pass for the actor being in a cold environment.

 

[AquariunGuru]

Spencers should have one or look on the net. What I wonder about is whether or not the stuff is good to breath in?

T.

 

[Joe999]

Relatively non-toxic, unless one suffers from asthma.
http://www.google.com/search?source=ig&hl=en&rlz=&q=toxicity+of+fogger+fluid&btnG=Google+Search

This article leans towards the more hazardous issues:
http://www.uic.edu/sph/glakes/harts1/HARTS_library/smokefog.txt

I am going to drive to the dry ice supplier soon and see if I can talk to a human about using dry ice. But for a cemetery / woods horror short the fogger machine would be a must. Maybe if I kept the amount low for the indoor shot, perhaps added some CGI particle effects to supplement? E.g. maybe use the fogger machine for fog behind the actor, then add particle CGI for sides and foreground? I wonder if After Effects can do ice fog effect? Or could the fog machine be done against a green screen, then layer that with footage shot with the actor but not using the fog chemical?

... What I wonder about is whether or not the stuff is good to breath in?

 

[Joe999]

Here is an interesting and useful site I just found on dry ice, complete with a dry ice supplier locator by telephone area code, and recipes for using fog (witches brew, etc):
http://www.dryiceinfo.com/fog.htm

A potential problem with dry ice is that it creates a LOW lying fog. What I need is a ice or cold type fog shrouding the actor. In the end, maybe I should just go with CGI?

 

[John@Bophe]

I used a fog machine for Halloween last year. I put the thing in the bushes outside my front door and sat right next to it to hand out candy. I was breathing the stuff all night, and aside from a few lingering twitches --- I think I'm okay. Seriously though, the one we got was pretty small and the fog juice label indicated it was safe. It did kick up a pretty nice floating fog that wafted down the street. Dry ice, on the other hand, is definitely low-lying. I think if you tried a fog machine you could create a nice atmospheric effect. We got ours for about $20 during Halloween time. Plus another $10 for an advanced timer control.

 

[spinner]

I used a fog machine for Halloween last year. I put the thing in the bushes outside my front door and sat right next to it to hand out candy. I was breathing the stuff all night, and aside from a few lingering twitches --- I think I'm okay. Seriously though, the one we got was pretty small and the fog juice label indicated it was safe. It did kick up a pretty nice floating fog that wafted down the street. Dry ice, on the other hand, is definitely low-lying. I think if you tried a fog machine you could create a nice atmospheric effect. We got ours for about $20 during Halloween time. Plus another $10 for an advanced timer control.

I remember seeing fog machines on sale at Walgreens and Rite-Aid for no more than $25 three years running...


-- spinner

 

[oakstreetphotovideo]

If you shot on a greenscreen, you could layer [CG] fog in front and in back of your subject. However, I'm not that impressed with the CG fog I've seen. If I were going the greenscreen route (which is something I do often), I would shoot a video of real fog on the water at night using a bright light to illuminate the fog from the front (which would leave the background and water totally black). Then I'd put the subject in front of my fog video, and screen a copy of the fog video over the top. I'm pretty sure that would look Ok, but it seems like it would be a lot simpler just to shoot with real fog!