Any number of channels can be written to an OpenEXR file. To create an OpenEXR output, use the Add button to add suitable channels to the format, and rename the channels if necessary. All data types supported by OpenEXR are available: 32 bit integer, 16 bit float (so called Half type) and 32 bit float. Channel type can be selected per channel.
For convenience, Realsoft 3D automatically maps the common channel names as follows: Color.R is renamed as R in OpenEXR writing, and Color.G and .B respectively. Alpha is renamed as A. This helps other applications to identify the data.