The photograph of this spiral petroglyph in Wrangell, Alaska, revealed more depth and detail by using an off-camera flash directed across the rock face at an angle.

I’m well aware that most photographers will never be in a situation that requires them to photograph petroglyphs or other rock carvings. But I’ve encountered etchings in stone on various trips and realized that the techniques required to photograph them can be applied to other subjects and situations. As with all photographs, the critical element is light and how it strikes an object. Petroglyphs can’t be turned to catch a nice angled light. Neither can many subjects; buildings, landscapes etc. So depending on what time of day you happen to be photographing a subject, it may be in unflattering light.

You have two ways to control the situation: You can explore different angles from which to photograph, observing how the quality of the light hitting your subject changes as you move. Or you can add your own light.

Several years ago I was photographing petroglyphs on a beach in Wrangell, Alaska. The mid-day light was at the wrong angle, and the rock carvings were not distinct. But I did have a point-and-shoot camera with a hot-shot that enabled me to use a flash and a flash cord. After picking the best position from which to take my photo, I placed the flash 6 feet away at what would be the 10 o’clock position, a 120-degree angle to the camera, and aimed it at the petroglyph. This created a directional light that would cross the face of the rock adding shadow detail. I underexposed the ambient scene slightly relying on the flash to illuminate the rock face, which further enhanced the petroglyph.

Recently I visited Alcove Spring near Blue Rapids. It is a famous ford where pioneer wagons following the Oregon Trail crossed the Big Blue River. A member of the Donner Party etched the name of the spring in stone in 1846, shortly before heading west where most of the party later froze or starved to death in the Sierras. Unfortunately, I didn’t have a flash with me and the carving was in shade. So I circled the rock, studying angles high and low until I found one that caught the light and added definition to the rock inscription.

I’ll end this column with a quote from Bertrand Russell: “The observer, when he seems to himself to be observing a stone, is really, if physics is to be believed, observing the effects of the stone upon himself.”