A camera is carried routinely in most field studies and should thus be
compact and strong. Older models of several of the top-grade 35 mm cameras
have retractable and exchangeable lenses as well as solid workings that make
them ideal, moderately priced field cameras. All 35 mm cameras have a
greater depth of focus than cameras with longer focal lengths, and this is a
decided advantage in photographing irregular outcrops at close range. A
wide-angle lens (as a 2.8 cm lens for a 35 mm camera) gives extreme depth of
focus (commonly 1 m to infinity) and a much fuller view of outcrops that
must be photographed at close range. A lightweight tripod permits longer
exposures and thus the reduced apertures required for maximum depth of
focus. A flash attachment may prove valuable, as described in Section 3-4.