ray_parkhurst
Joined: 20 Nov 2010 Posts: 1185 Location: Santa Clara, CA, USA
|
Posted: Wed Dec 20, 2017 6:03 pm Post subject: |
|
|
Robert...this may have been mentioned, but have you considered doing a 3D rendering of the stacks in order to compare the field flatness of these objectives? I did that a while back and it was useful. I used a flat surface (your wafer will be much better) and the rendering gave me a good indication of the shape of the focused surface. As I remember, one of the objectives I tested had decent sharpness at the corners, but the field un-flatness was so severe that it took an inordinate number of shots to get the whole surface in focus. So although it "could" produce a sharp image of the whole surface, it was not practical. A true plan objective could do the same job in just a few shots. |
|