How to Haze a Room?

[Stevo]

I'm a student photographing a film next week, and I want to use a haze machine to achieve the "visible sunlight" streaming in through the windows look. My question is: How much haze should one use? Does it photograph accurate to the eye? All I've been told thus far is that it's hard. If anyone has any tips on how to accomplish this, I would really appreciate it. Thanks.

 

-Stevo

[Phil Rhodes]

Hi,

 

I use this stuff all the time as I'm generally shooting video and it's a help with contrast. The problem I find is not getting the effect, but getting it to be even and consistent over time. Without automatic sensing equipment (which does exist) it's hard to avoid the level of smoke fluctuating as it dissipates - get the long persistence fluid, which makes it a lot easier, and have a couple of people standing by with poly boards to beat it into a fine mist.

 

Phil

[David Mullen ASC]

It's really done by eye in terms of maintaining a consistent level, which is why it's a good idea to keep the room sealed and use a smoke that hangs well so you aren't refilling the space on every take, but just trickling the smoke in all day long to maintain it. This is where the more expensive hazemakers are better than a small Rosco or Mole fogger.

 

The deal with smoke is that it cannot be contained to one part of a room -- it will move until it fills a space evenly, so you have to smoke even the off-camera areas of the same space and keep windows and doors shut. Usually you start out over-smoking the room until it dissappates and fills the room, and then just augment from there as the smoke level drops.

 

The smoke will look heavier when it is backlit, so I find it looks better to use less smoke and more backlight rather than more smoke and less backlight.

[Michael Nash]

It depends on what you use to create the haze. General purpose "party" foggers (the kind night clubs use) put out great clouds of billowy white smoke which can fill up a room quickly, but the fog tends to dissipate rather quickly even in a sealed room. You usually have to "fog it up" really good right before you roll, and have a couple people with small flags as "wafters" distributing the smoke around the room. Give it just a minute to settle, and you've got a good haze for the length of the take. Don't be afraid to overfill the room at first as you'll need the excess to disperse to avoid thick/thin patches.

 

Even better though are haze machines such as the DF-50. It puts out a lighter foggy haze with better hang time, but not billowy clouds. It never really gets too dense, just a thicker haze.

 

There is also haze that comes in a spray can, good for small spaces or isolated parts of a set. It doesn't get too dense but it's got great hang time.

 

In all cases you have to keep the room sealed so you don't lose the fog. Fog shows up best when it's backlit, against a dark background. How well it compares to what you see by eye depends on contrast of the format you're using. In other words, a high contrast film stock might bury the haze that's in the shadows but also make the light shafts stand out more prominently. Just judge it by eye.

 

http://www.texasscenic.com/speffects.html

[Laurent Andrieux]

My contribution to this would be

 

- wait until the haze has well dissipated before rolling as it doesn't move during the take (everybody's always in a hurry for yieling "roll them")

 

- "stop da smoke" I mean, there is often too much... You put quite some at the beginnig, then it dissipates and you think, by eye, it has sort of disapeared... it hasn't.

 

- If you use carboxylic ice it stays down the floor. With machines, it disappeares faster. The best is to have both.

[Phil Rhodes]

Hi,

 

You can get fog machine controllers with an infra-red detector to automatically maintain a level of haze. In my experience they need an hour or so to achieve some kind of equilibrium, but it's very convenient.

 

Phil

[Bob Hayes]

Haze machines like the DF-50 are the way to go. They hang longer and look less like the set is on fire.

 

I own one of those cheap disco foggers and I keep it on the camera truck. On shows where I don?t have an effects team it has come in pretty handy. I?ve found the best way to use this style is to point it away from the set. Point a fan at it and try to break up the clouds. The trick is to fill the off set areas and let it drift into the set. When you cut the camera run the smoker for a bit. I also use a small light like a Tweenie to back light the smoke right in front of the camera. I leave it off unless I feel I?ve lost too much foreground smoke then I click it on to lower the contrast.

[Alvin Pingol]

Speaking of haze/fog...

 

I know that most all of the "fog juice" produced today is fairly safe to inhale, so long as it's not excessive inhalation, but when does it become a major concern for the saftey of the equipment on set?

 

The fog or haze must go somewhere after it dissipates, and where it goes is fall to earth and build up on any surface it sticks to. Those who pan-fry things know what I'm talking about, in that small droplets of oil form on surfaces that are too far to simply have been "splattered" on if one doesn't use an oil screen. I find small oil deposits on cabinets accross the kitchen.

 

Anyway, if one uses a fogger or hazemaker in a heavily artifically lit room, couldn't the "juice" deposit on the lights and potentially ignite due to the extremely high temperatures on the surfaces of the units?

[Phil Rhodes]

Hi,

 

Yes, it does deposit, although it's so little as to be insignificant. I've been into bits of intelligent lighting equipment that've been sticky with the stuff, but that's after years of nightly service in a club.

 

No, it's nonflammable, or at least the stuff I've used is.

 

Both scenarios are critical on the equipment being in good order. A machine which undercooks the oil will result in bigger droplets and increased precipitation

Overcook it and it will burn, resulting in carbon compounds which can be carcinogenic. Overcooking the oil is a major safety concern with this kind of equipment.

 

Information based on that gleaned from UK company Jem while in daily contact with their ZR20 generator.

 

Phil

[rhinoceroz]

how about this thing:

http://store.yahoo.com/cinemasupplies/diffusionincan.html

 

fog in a can!

[Mitch Gross]

how about this thing:

http://store.yahoo.com/cinemasupplies/diffusionincan.html

 

fog in a can!

In practice I've found it useless.

[Michael Nash]

I actually thought it had pretty good hang time, just not good for large rooms or lengthy scenes. It's not bad for last-minute additions to a particular shaft of light. Something you can carry in your kit and use for the odd shot.

[Alvin Pingol]

...bits of intelligent lighting equipment that've been sticky with the stuff, but that's after years of nightly service in a club...

Ah, so it takes years before the deposits start becoming gross and sticky. Got it.

 

That fog in a can stuff looks interesting. I didn't even know they made that, and just because of that, I think I'll buy a can. :D

[Phil Rhodes]

Hi,

 

That's smoke machines. Oil crackers can be really really filthy.

 

Phil

[Phil Connolly]

I've only used a smoke machine once on a film, looked great, but setting off the smoke detectors and fire alarm was less great. :rolleyes:

 

Still won't make that mistake again.

[Luke Prendergast]

If you use vegetable oil in a cracker you get a nice deep-fried chip kind of aroma all through the set, your clothing, equipment...

[Dan Salzmann]

Bee smokers can be useful for smaller rooms.

[Paul Bruening]

We had similar issues with gun smoke from blanks on our last feature. Back light and side light is definetly the best way to get the most out of any smoke. Don't choke up your cast and crew trying to smoke up a front-sided lit set.

 

Paul Bruening

[Jayson Crothers]

Bee smokers can be useful for smaller rooms.

Blech; bee smokers look fantastic, very heavy and good hang, but the smell that seeps into EVERYTHING isn't worth it......I still have clothes that smell of it months and months and months later.

[Dan Salzmann]

It depends on what you put in the bee smoker. Ordinary corrugated cardboard works and sure is easy to find. Bee smokers are good for smaller applications, ie. to reinforce a shaft of light or a smoky card game.

[Matt Pacini]

Ha ha!

That brings back some bad memories.

I did this in the Auburn Courthouse where I shot a scene from my film Lost Tribes.

(They used this location in Phenomenom also).

Fogged a room that is basically a museum of old original entries of prisoners of the jail, old guns used by sheriffs in the 1800's, etc.

The alarm went off, and I just about had a stroke waiting for the sprinklers to go off and destroy all this priceless antique historical stuff!!!!!

Luckily it didn't, but they had to evacuate the entire 3 story building, and nobody had a key to the alarm, so we waited around until they could call someone to shut it off.

Meanwhile, multiple firetrucks start showing up, and I'm running up the dollar signs in my head.

That's the great thing about filming in a small town.

Everyone laughed it off, didn't charge me anything, and I even got to come back for reshoots!

 

Matt Pacini

[andres]

Hello there.

 

I once used a smokemachine and we shoot a video on 16mm. It was not a hazer but a cheap disco fogger. When i came to the telecine to make a copy to tape one problem came up. When you have to much smoke in the room made by a disco fogger and want to push the colers to the max, you could end up like I did and have very disaturated coulers. When you try to get max out of the coulor you ending up with more grain, because the smoke disaturates the pictures and you push the film to hard. So keep in mind not to have to much smoke and dont use a cheap disco fogger.

 

regards

Andrés