Addendum to Paul....

Before thorough reviewing of your data and internet research it has occured to me, (armed with your enlightened statements), if I can select a star magnitude and mask hole diameter appropriate for my particular focal ratio and ocular....it might be possible to use Hartmann technology to acquire diffraction rings from each hole or at worse....diffraction rings at critical focus to achieve a "super state" of focus from the outer rings essentially acting as a focus magnifier by their greater apparent diameter. You have stimulated dormant brain cells now and it is exciting but could be futile due to refraction at hole edges. Was able to download all 4 focusing articles of your reference in Adobe for additional reading. Tnx.-Larry