ExpoDev supports two exposure metering modes to choose from, Incident and Zone mode. Incident mode is for using the BTZS method of incident metering. Using Zone mode allows you to place subject elements on Zone System print zones, typically by assigning shadows and highlights to the Zone III and Zone VII zones.
The metering EV values may be set using a scale of tenths or thirds, as set in the App Settings. Zones are always assigned in tenths. In Incident mode the EV range is -10.0 to 20.0. In Zone mode, the EV range is 0.0 to 20.0.
In either mode ExpoDev will calculate and display the Subject Brightness Range (SBR) of the scene as well as the Average Gradient (G) and the Effective Film Speed (EFS). If your metering choices are invalid or the metering choices are beyond the capabilities of the selected film profile, ExpoDev will let you know so that you can make adjustments.
There is also a place to enter general metering notes which is especially useful for recording where you took your meter readings, the scene's lighting conditions, etc...