In Hemisfer (from version 3.0 onwards), there are two different modes of leaf area estimation, either for the LAI of a canopy or for the leaf area of a single tree. While the first one gives a dimensionless number because it is the leaf area relative to the ground area, the second one gives an absolute number, typically in square metres. Actually, no unit is specifically defined in Hemisfer: if the user enters the position and size of the tree in metres, then the leaf area will be in square metres, but these could e. g. also be feet and square feet for those who still don't use SI units. For each mode, there is a specific tab of the options dialogue. Checking either mode (canopy LAI or single tree) deactivates the other one because it would not make sense to estimate both at the same time.
In the "crown" tab of the options, the user can enter the shape and size of the pictured tree crown and set the relative position of the camera. While doing this, a small map and a small side view are displayed to check how the tree looks like and where the camera is positioned. Note that the side view can be rotated by adjusting its azimut. Once these data are accepted by clicking on the OK button, the main window of Hemisfer will show the hypothesised shape of the tree as a green grid delineated over the photograph. This way, the user can check if the entered data are plausible compared to the photograph, as for example in the picture below.
The output of a single-tree leaf area analysis is a plain-text results file.