Prehistoric Petroglyphs near the desert lab. This image is a mosaic from 2 frames of 3 exposures each.? The intent was to capture a range of tones and a perspective that the eye can see in a scene, but can not usually be contained in a single photograph. It’s like the composite image you would have if you looked around a bit, shifted your gaze to the rocks, then to the distant mountains.? These images are all from the same site.