Lighting is a huge factor in shooting caves. Most videos on YouTube are dark and you cannot see the detail, making them not very interesting to watch. For a typical cave, I pack in these lights:
* XeVision Barn Burner - 80W HID
* Henlin SL-3570 - 70W HID
* Home-Made 100W HID
* FireFox FF4
The first three lights are generally enough to light up most spaces. If I know the cave has a really BIG room, I'll also pack in my Modified Vector.
http://www.candlepowerforums.com/vb/showthread.php?272969-Vector-192-BFL-172W-Dual-Beam-Build
I use the FireFox FF4 for lighting up a smaller area.
Video - Camcorder:
You also need to find a camcorder that performs well in low light. That feature is usually affiliated with the size of the processor. The larger the processor, the better the camera does in low light. I also use a wide angle lens in most shots.
Video - GoPro:
All helmet cameras to date are designed to be used during daylight hours. That means they have a smaller processor than camcorders. That being the case, you need a lot of light for the video to not look pixelated. I use the helmet mounted GoPro when I need my hands free for climbing or squeezing through tight areas. That means you can't hold a powerful light in your hands, but have to rely on the light mounted to your helmet. That being said, you need to have something that puts out at least 1000 lumens in my opinion (i.e.Zebra Light). If you can find a brighter helmet light, that would be even better. Also, GoPro footage should only be shot in smaller passages because they do so poorly in low light conditions. I'll be looking to upgrade to a GoPro Hero5 or an YI 4k+ (not out yet) this year.
Prehistoric Evidence
I read an article where the owners found a wall built in the cave by aboriginal people. Actually, TN has a lot of caves where evidence has been found where aboriginal people lived in them...Big Bone Cave, SaltPeter Cave, etc. In some of these caves, they have found artwork, evidence of mining, dried weed stalk torches, etc. What kills me is that these people from long ago went deep into a cave with only a torch. From a caver's point of view, if your light goes out when you're in a cave, you're in some deep trouble. Without any light, you'll never find your way out. That's why you 1) Always pack in three sources of light along with spare batteries and 2) always tell someone where you are going, so if you don't show up the next day they know to come looking for you.
Thanks for the comments.