5 Tips for using a fog machine for studio photography
Fog adds a cool look and atmosphere to a studio shoot. I bought a fog machine at a local party supply store and got an extra bottle of “fog juice”. One bottle lasts for a long time so I have plenty of it left, even after using it for about a dozen shoots. This fog machine has a handy remote control that lets me fire a blast of fog when I’m ready to shoot. They are pretty popular for Halloween so you may see them for sale for a good price at this time of year.
The type of machine I use is a “glycol fogger” and it works by heating up a fluid called “fog juice” and then shooting the fog out of a nozzle. Since I am a chemist as well as a photographer, I needed to know what fog juice actually is. It is mainly glycerin, propylene glycol and water and is non-toxic (note – a similar sounding chemical – ethylene glycol – is toxic and should not be used for fog machines!). However, there is always the possibility that certain people could be sensitive to the glycerin and propylene glycol so it’s a good idea to make sure everyone is OK with it when the fog starts.
There are other ways to generate fog. For example, dry ice and water works, but it’s expensive and difficult to use. Dry ice must be handled carefully because it is extremely cold and will burn bare skin. Because dry ice produces carbon dioxide gas when it warms up, it should be used in well-ventilated areas, and never in small enclosed spaces due to the risk of suffocation. The fog is colder than the surrounding air and will sink to the ground, which might be an interesting effect. The fog from the glycol fogger doesn’t sink – it tends to float at the level where it was generated.
Here are some tips based on my experience with using the fog machine.
The fog needs lighting to make it visible. Back lighting with the strobe out-of-frame or hidden behind the model looks great. Also, side lighting works well as shown in the shot of Kaitlin V. I use a hard light – usually a strobe with a tight grid or snoot to give a beam of light through the fog. Use the same precautions that you would normally use when potentially shooting into the light – use flags to shield the lens and avoid lens flare. Sometimes a bit of flare looks cool with the fog so you may want to experiment!
Use a dark background
The fog is white and does not show up against light backgrounds. Use a dark background such as black seamless paper or black fabric for the most dramatic look. I learned that the hard way when I tried shooting against a white background and the fog was hardly visible!
You can change the colour of the fog by putting a gel on the strobe that’s lighting the fog. You can also light the fog with two strobes, using gels with harmonizing colours to create a dramatic look.
Have an assistant
It helps a lot to have an assistant (for me it’s usually the makeup artist!) to direct the fog by pointing the machine in the right place – usually in front of the lights or behind the model. I use a light weight fog machine so it is not too difficult to hold for a while. Some of the more industrial grade machines are heavier so you need a strong “fog wrangler” for the job! Make sure the assistant knows that the nozzle of the fog machine can get quite hot! I get my assistant to move the fog machine in the right place, then let her know when I’m going to blast some fog with the remote control.
The best looking fog is usually very soon after it comes out of the machine. This is when you get lots of swirling, smoky fog. It quickly diffuses and after a while it dissipates through the studio, creating a haze that doesn’t look so great. When there’s too much fog between the camera and the model, it just reduces the contrast. If I’m doing several sets, I usually wait until the end for the fog, or open up the studio after a while and blow it out with an electric fan!
Don’t forget to have fun and experiment with it! If you have some tips for using fog in photography, please share them in the comment section.