All you have to do is this:
1.Handle with Care
En route to the caves you want to explore and photograph, you might have to walk on two legs or even four. In such cases, use a backpack to carry your accoutrements. Protect the camera because even a slight fall on a rock can reduce it to smithereens. Carry it in a waist belt with a pocket and keep an eye on it as this pouch will prove indispensable. There may even be a sudden downpour when you cannot afford to expose your camera, so you’ll be glad you have it. Also make sure you keep a cloth handy once you enter the cave, because water can drip from the ceiling. Carry a soft cloth to keep wiping out the moisture and place to over the camera while shooting if need be. The water might have several undesirable minerals.
2.Wear A Headlamp
Use a headlamp, because not only will it act as a flash and help you focus easily as your hands will be free , but it will also act as torch for you to maneuver in the cave and shift positions easily to set your tripod up. Along with an off-camera flash , this headlamp will be the primary light source. An LED headlamp has temperature closest to that of the flash.
3.Use A tripod stand
You cannot stand on uneven surfaces and completely concentrate on the shooting because you cannot walk around freely as you would on even ground. That’s why a tripod is a must-have. It will help you position the camera with ease, and at a safe place and elevation.
4.Use a Wireless Shutter or Timer
Find a camera that has a wireless, remote-controlled shutter or use one with a self-timer. Avoid shakes in your picture by using a cable to decrease it if you want the shutter to stay open for longer than the camera’s slowest speed. Set the self-timer as well, once you have stationed it in the right place.
5.Let your lens be a wide one
Caves cannot be said to be of a particular shape. Whatever it is, be prepared to take shots that are mostly wide-angled. Start off with a size of 18mm for an APS size sensor or 28mm for full frame. A 16-35mm zoom will give you amazing width without fail. Do not neglect the smaller ones either as you might have to shoot smaller angles as well. Handle the lenses carefully and protect them from moisture.
6.Get an external flash device
Photographs taken with cameras with a built-in flash, lack depth and proper lighting. They look flat and two-dimensional. Instead, get an off-camera flash to introduce shadows and extra depth to the image. If you use more than one flash, you can try getting extra optical features into your photography.
Try more RAW in your shooting
Shooting with this mode helps because it gives you maximum latitude in the darkroom for both the flash and the exposure you set.
7.Adjust the ISO to a low value
It is better to have a low ISO because in spite of the flash, your might spot a few black patches here and there in your final image. An ISO value of about 800 is acceptable. Go lower to about 640 and you will have felt that you could have perhaps gone lower than that. Decide the right value depending upon the capabilities of your camera.
8.The longer the shutter time, the better
Leave the shutter open for about 30 seconds and then illuminate the field. Hot spots might be present on the CCD which will show up only after processing because you exposed for too long. Handle these later once you obtain the image. Or speed up the operation.
9.Shoot people as well!
Have a reference point for every picture you click. Don’t include a human in a close-up shot because it defeats the objective which is photographing the cave. Have someone standing in all your wide angle shots and make sure they stand absolutely still because the longer shutter speed might cause their image to go blurry. Make them move around if you are planning for multiple shots. Get a ghostly image by making them move out of a lit area. Try different settings!
10.Turn the flash off!
Try not to use the flash. Instead, illuminate the walls using torches or lanterns after setting the camera for very long exposures. Use colour filters to make the shots more interesting and unusual. Expose the camera and then illuminate using a carbide lamp or a candle as these can light up even huge dark voids. This works only for caves that are completely dark and are situated underground with absolutely no stray lights.