How do movies make explosions?

Question

In just about every war film, there is always an explosion of some sort.

What do film makers use to make an explosion that looks real and is completely harmless?

Answer 1

What do film makers use to make an explosion that looks real and is completely harmless?

They don't...they aren't harmless.

It will depend on the size of the explosion but they use real explosives, just less than you might think.

Again, depending on the effect you are after, an explosion can be made to look bigger or more effective by using light-weight debris (usually made of light wood, say balsa) or perhaps polystyrene to simulate much larger and heaver elements.

In many cases though explosions can be enhanced by adding more fire and this is simply done by adding gasoline/petrol to the explosion.

Special effects such as explosions are conducted under close scrutiny and will be carried out under strict safety protocols and there will usually be a dedicated person (or even a team) who control how things are done.

Of course, explosions can now be enhanced (if not completely created) with CGI but it's more likely that a real small explosion will be conducted and, if necessary for safety reasons handed over to the digital effects team.