Steven Spielberg can get away with hot, smoky light coming from beneath the lost Ark of the Covenant, buried for 2,000 years in a crypt. We can't.
There is a logic to light. It's gotta come from somewhere and something has to be making it. That's why it doesn't really make sense to have somebody in a field staring at a hole in the ground with light coming from the hole. Unless you're shooting production stills for The X-Files.
Try to be logical and give your reader something to hang onto. I often use a flashlight, which creates a reason for the light, plus it's something you'd actually use if you were looking under a car hood, reading a map, of checking out a torpedo tube.
[How do you get this type of shot]
Small and light is the way to go onboard a sub. I brought three small SB flashes with me, bounced one to open up the dark recesses of the torpedo room, and then placed a double-gelled unit inside the tube, lighting the sailor's face.
Excerpted from: The Moment It Clicks. Photography secrets from one of the world's top shooters. By Joe McNally, Copyright 2008 Used with permission of Pearson Education, Inc. and New Riders.