Depth-Of-Field Calculator (c) 2001 M.J. Kemps For PSION Siena and Series 3. This program is Freeware. You can contact the author at kempsmj@hotmail.com INSTALLATION: Copy DOF.OPA to the OPA directory on your psion. Use Psi-I to install. Initial release: 12-02-2001 Version 1.1 released 13-02-2001 - Bugfix: Distances shorter than 1.7m did stop the program with an error.