We did this stock shot of three models watching a scary 3-d movie in the studio yesterday. Two lights were used: a tungsten light from behind to mimic the film projector bulb, plus a Nikon SB-900 mounted on the camera and pointed directly at the models to mimic the light coming from the movie screen. The SB-900 had a Vello 8" Snoot/Reflector wrapped around it to form a snoot that focused the beam of light making it more directional. The camera was a Nikon D800. The flying popcorn was not retouched. It was frozen by the flash in a mid-air spill, as the model tossed it into the air. Sometimes you just get lucky.