Though you might think this was a capacitor designed for use during movie shoots, rather, this is a capacitor constructed using a polymer (plastic) film, such as polycarbonate, polystyrene, polypropylene, Mylar (polyester), and metal foil. The basic idea is to create a dielectric (an insulating layer between conductive layers) by taking plastic film and rolling it up with aluminum or copper foil. Film capacitors are highly stable, and deal well with high frequencies, making them a good choice for filters and other signal applications.
