Buffalo Lava Caves, Craters of the Moon National Monument

Entering the cave - not too much clearance!  I bumped my head a couple times....  We left most of our backpacks at the entrance.  This image taken with my 24mm lens with an exposure of 1/250 seconds at f/8, ISO 100.

A view of some of the stalactites hanging from the ceiling of the lava cave - these are not caused by the usual dripping calcium Carbonate but instead by the rock on the cave wall melting in the heat of the lava flowing through the cave below it.  This image was taken with my 24mm lens with an exposure of 1/800 seconds at f/1.8, ISO 3200 with a flashlight illuminating the central part of the image.

A view of more stalactites in the lava cave - smaller in this case than the first image.  This image is the combination of 2 images each with the flashlight pointed at slightly different parts of the ceiling , the exposures were 1/50 and 1/200 seconds, both at f/1.8, ISO 3200 with my 24mm lens.

Looking back at the entrance to the cave.  You can see the rough surface of the ceiling, covered in stalactites as well as the complex structure of the floor.  This image was taken with my 24mm lens with an exposure of 1/60 seconds at f/1.8, ISO 3200.

These last two photos are different views of the same section of a collapsed cave section.  The ceiling was around 3 or 4 feet thick before its collapse.  In the upper image, you can see some horizontal banding in the cave wall which  are the result of lava flows of differing depths when this was an active lava tube.  I forgot to reset my camera for outdoors shooting after climbing out of the cave, so the first image was taken at 1/4000 seconds at f/1.8, ISO 3200, the 2nd (after the D'Oh! moment) was taken at 1/25 seconds at f/8, ISO 100, both with my 24mm lens.