The alternate design I have seen/read involves a Hartmann mask where the holes are equilateral triangles. The philosophy is that once the triangles converge, you will be able to identify it as such much easier than trying to locate the sweet spot for three circles. I also recall reading the results of a spectropic analysis done by a fellow in Japan (?) who demonstrated using physics that the use of three circles is the least attractive option. His testing showed that two trianges and a circle (from what I remember) was the optimal design. Time permitting later today, I will try and dig up the URL from Japan.
Anthony.
DnlMahoney@aol.com wrote:
I recall reading something about a focusing mask that incorporated holes that were not round. Does anyone out there have any experience or ideas about variations of the Hartman focusing mask? Also, what effect do the hole sizes and locations have on the focusing outcome?Clear skies,
Dan Mahoney
http://members.aol.com/dnlmahoney