I’m sorry to have kept you waiting. Let’s start shooting now.
Back in the day, you'd use shadows to photograph things. Now it's all fancy and digital. So, with that in mind, a photograph shadow was someone doing a photoshoot of some kind. And, in even more modern times, it has become a movie shoot as well. More simply, it can be photographing or filming as well. Basically, if it has to do with taking photos or video, 撮影 is your dude.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.