Caves tend to be very dark places. Cave walls will absorb a lot of light. The good news is that you can shoot with very long exposures, assuming a good tripod.
One old cave photography stunt is this:
Put the camera on a solid tripod with a shutter remote cord and with the lens cap on. Have your lighting assistant walk out to about twenty feet with a manual flash gun. Start the shutter with the lens cap on and lock the shutter open. Remove the lens cap without jiggling it. The assistant fires the manual flash gun a the first target. Then you re-cap the lens, still with the shutter locked open. The assistant moves out to twenty five feet, and you repeat the process. When the assistant has fired the last flash, then you unlock the shutter so it closes. You can get five or six different flash pops adding up to illuminate a long passage that way.
Caves seldom have much color. So, using colored flood lights and gels and filters might be some help. Or, you might try to goose up the color in your editor.
---Bob Gross---
