The FCV started using small format photography in forest management in the early 1970s.
"Aerial photography is often required to record local changes in the years between major surveys or to provide additional detail in selected areas. Such information may include details of species and growth, or changes such as new roads, tracks, firebreaks, boundaries of clearfellings, replantings, burns, insect and disease attack and so on."
"For these purposes, simple, cheap and rapid methods of obtaining supplementary photographs using 70mm and 35mm cameras have been developed."
See: Small Format Aerial Photography, R Spencer, VSFA Newsletter 30 (May 1972) p43.