Information on Photographic Techniques for Petroglyph Photography Photographic Techniques by James Martin Petroglyphs can be maddeningly difficult to photograph. They are almost always located in a remote area. Trudging to them with the 100 pounds or so of equipment that might be required to light and photograph them properly is generally inadvisable, especially in the tropics in summer. The engraved or pecked lines may be so shallow as to be almost invisible.
Erosion can make any petroglyph faint enough to be missed by the casual observer.
A little background is in order. On Ometepe Island, the depth of the engraved lines on recorded petroglyphs varies from immeasurably shallow to around three centimeters. This petroglyph is found on a nearly vertical slab of basalt bedrock. The panel measures 210cm high by 300 cm wide. Another slab of basalt immediately adjacent and at a right angle to R29 contains another human figure similar to the 5 found in R29.