Cinematography Mailing List - CML

Smoke/Hazer Effect

I need to try and convince a museum to allow the use of a hazer. Obviously a water based, non-residue, fluid would be required. The shoot is a museum at night, fairly dramatic, spooky-scary kind of light. The haze does not have to be real thick, we only want to bring atmosphere and beam definition to the scene.

Any one have any ideas as to what arguments could be brought to the table?

It seems that various type of glycerine or glycol are used in these water based hazer fluids.

John Roche, gaffer

>>I need to try and convince a museum to allow the use of a hazer. >>Obviously a water based, non-residue, fluid would be required.

The most suitable haze for such a delicate environment would be a standard medium persistence smoke fluid which is typically based on triethylene glycol. Used VERY sparingly to just haze up the atmosphere it should cause no problems with the surrounding artefacts. The triethylene glycol based fluids tend to be the cleanest in terms of minimising residue. To offer greater control in density without huge clouds of fog, the fluid can be watered down with pure distilled water if desired.

High persistence fog fluid based on glycerol is not recommended since it does tend to leave a residue.

Oil based haze while producing excellent haze with a minimum of oil, still does tend to leave an ultra-slight coating of mineral oil on the surrounding area. (If a genuine well maintained oil cracker is used!)

The aerosol based haze makers (smoke in a can) do put out a significant amount of mineral oil I believe.

Water fog, liquid nitrogen, carbon dioxide or dry ice (solid carbon dioxide) would only produce a short lived fog with a lot of residual moisture.

I think this scenario is all down to using a standard smoke fluid and machine at the minimum level required to create the haze. The almost legendary hand-held mini-mist would be perfect for this application. Make sure air conditioning equipment is off to minimise the amount needed and have someone man the alarm system just in case very sensitive detectors are being used.

The standard foggers are quite noisy and almost always tend to snort extra bursts of fog out randomly with a whoosh noise as the fluid expands, so the fogger would have to be removed from the area during a take. The glycol haze machines tend to produce a pulsating hiss noise as they slowly squirt little bursts of fog into a diffusing fan.

Clive Mitchell

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