Now THAT'S lighting.

Darn!
The document wouldn't upload.It's from "National Geographic Adventure:First Photo of Titanic Cave".

Superb!

Are those people holding the lamps?

<edit> Just noticed the person halfway down the caving ladder! That is some cavern!

Looks like Rumbling Falls Cave here in Georgia. I gotta tell ya, shooting in a cave is pretty darn hard to do. Especially the big room shots. I've done a bit and I've never been able to get enough light together to light a large room. They still use flashbulbs for that kind of work, electronic flash is a bit dangerous in that damp environment for really high power levels so you don't see too many people doing it.

Sweet cheeses, it's as if you're looking up the bowels of a big monster!

Amazing scale.

Gary nailed it.Rumbling Falls Cave.
Andy , they are using hand lamps.The photographer gathered a team of cavers to lug his gear.

If someone can email me I'll send them the article.They may have a better chance to post it for all to read.

Mike