This is a fog generator- dry ice, water, and a bucket. Warm water works better than cold for producing gas, and if your generator slows down, a dash of hot water in the bucket will certainly speed things up again.

It helps to build a dam to encourage the cold gas to stay put. That way it doesn’t immediately flow off in the lowest direction. Because the gas is cold, it will naturally seek out the lowest areas.

WARNING- I had to say that. Dry ice is very cold and can cause frostbite. I have no trouble picking it up with my bare hands, but you should use common sense. Also, the gas produces as it sublimes displaces the stuff you can breathe, i.e. oxygen, so use common sense here too. Don’t put huge quantities of dry ice into hot water in small enclosed spaces and expect to breathe anything useful.

When dry ice sublimes (melts) it creates fog. Placing the dry ice in water really accelerates the process. It’s fairly easy to create dense low clouds of fog, which can really be used to advantage for photographing models.

To take photos like these with dry ice, you need a tripod, timer or cable release, and some patience. Still air really helps things settle, so if you have a central heating, turn it off, so you have calm weather conditions.

You don’t need much dry ice for good special effects with 4mm scale models. A half pound will give you quite a bit of gas. If you have children, buy even more. Playing with dry ice is a fairly educational way to get into subjects like sublimation…