If you visit a cave, you might want to take a few pictures home. Unfortnately this is rather difficult, at least if you want good pictures. It is essential to have the necessary equipment. Fortunately modern digital cameras are getting continually better and so even simple cameras are sufficient, if some tricks are used. It is important to differenciate between show caves with electric light and unlit caves.
The essential idea about taking pictures of show caves is to use the existing light, this is called available light photography. The lamps are placed for good effect, so half the work is already done. This has another important advantage, the humidity in the air will not reflect the flashlight and there will be no ghosts.
The essential thing with photography in dark caves is obviously the lack of light. As a result there will be no light for the auto focus and no light for the picture. It is easy to understand, that this will require some equipment.