I have always marveled at underwater photographers who take spectacular photos in a cavern or grotto when there is light coming in through a hole in the ceiling. I love the look of the light rays penetrating the dark space and illuminating it in an ethereal way. I really wanted to make a photo like the ones that I admired but never had the opportunity to try.
On our recent trip to the Cayman Islands, we made our last dive at Devil’s Grotto off Grand Cayman Island. Cathy Church says that this dive spot is the “Holy Grail” of underwater photography. When I entered the water and started to swim around, I had a hard time understanding the statement. Once I found my first cavern/grotto, all that changed for me.
The first lesson in cavern/grotto photography is that it is all about “LIGHT”. I decided that I would only use available light and not try to complicate things with a strobe. The first enclosed area that I entered was filled with Atlantic silversides, a schooling fish that presents an underwater ballet when in motion.
The first thing that I looked for was to find a position where the light made the silversides look the best. I was on the entrance side of the cavern/grotto and soon moved deeper into the enclosed area and found that I liked the look of the silversides lit by the sunlight. I used an ISO of 200, a lens opening of f8 and a shutter speed of 1/15th of a second for the photo above. I later had to increase the ISO to make up for the lack of sunlight. You also have to realize that you cannot expose for the brightest area because the remainder of the photo will be too dark. I accepted some overexposed areas to get the rest of the photo lit the way that I wanted it.
As I was photographing the silversides, a fish flashed into the school from an adjacent passageway. It was a tarpon. While I photographed, this scenario repeated itself. I tried to anticipate when it would happen but that was extremely difficult. The speed of the fish also made it difficult to freeze the fish in the picture. I kept at it and although the fish was not always sharp, the feeling of movement made the photo work for me.
This photo was also taken at ISO 200 with a lens opening of f8 and a shutter speed of 1/15th of a second. In hind sight, I could have used a higher ISO which would have let me use a faster shutter speed to freeze the tarpon better. Many of my photos are much better when using hind sight. I wish I could find it when I need it.
Digital photography has made this type of photography much less difficult. Using histograms and LCD screens, I could see the results of my efforts. Actually, the histogram isn’t as much use in this situation as the LCD view of the just-shoot photo was to me. I moved deeper into the cavern/grotto to get the photo that I was really after. It got much darker and I dialed my ISO to 640. I took a series of photos with the same ISO setting, the same lens opening and varied the shutter speed on each shot. See what you think of the difference. I am including the histogram of each of the photos.
This is the histogram for the photo above. There is a spike on the right hand side that reflects the brightness from the sun coming through the roof of the cavern/grotto. The build up on the left hand side is from all the dark areas.
This histogram looks almost exactly the same as the one above. The change in shutter speed is subtle but the longer shutter speed lets more light in. Look right above my copyright notice and you will see that the dark area is a light lighter.
Again, the histogram looks the same but the photo has changed. You can see that the sand on the floor of the cavern/grotto has gotten much brighter as has the area in the ceiling where the light is coming in from the outside. The changes in shutter speed were subtle but they made a difference in the finished product.
I guess the question left is “did I get the photo that I wanted?” The answer is YES and NO. I did get some photos that I was very pleased with. I wish that I had a model to work with on some of these shots but that is not always possible.
I was very pleased with the photo above. If I don’t get another chance to try this type of photography again, I will not be disappointed in my efforts. If you would like to see more of my photos from the Devil’s Grotto, you can visit my Photo Gallery or click here. I am in the process of putting a new photo gallery program on my website. At one point it will be my main program. If you would like a preview of the Devil’s Grotto in the new program, go here.
© 2010, Herb Segars. All rights reserved.
