4.4.8When You cannot Correct Astigmatism
If astigmatism still remains at the maximum correction level (One (and/or both) of Stigma sliders is set at the maximum or the minimum, or one (and/or both) of Stigma knobs on the operation panel is full), check the followings.
(1)Check if your specimen is ferromagnetic. If it is, operate at working distance of 12mm or longer, or use Magnetic Sample mode.
(2)Open the Alignment dialog window and start Aperture Alignment mode. If image is wobbling, carry out aperture alignment.
(3)Use other opening of the objective lens aperture. If you can correct astigmatism, use the opening or make cleaning of the aperture plate referring to instruction manual.
If astigmatism correction is difficult by shift of image during correction, open the Alignment dialog window and carry out aperture alignment and stigma alignment.
If you still have troubles, contact a service engineer.
4.4.9When Auto Focus or Auto Stigma does not Work Satisfactorily
When auto focus or auto stigma does not result sharp images, check the followings.
(1)Check if the observing specimen has fine surface structure. If it does not, please use manual focus and manual astigmatism correction.
(2)Open the Alignment dialog window and start Aperture Alignment mode. If image is wobbling, carry out aperture alignment.
(3)Open the Alignment dialog window and start Stigma Alignment mode. If image is wobbling, carry out stigma alignment.
(4)Note that Auto focus searches only a narrow area of focus when used at magnification higher than x5000. It will not work when quite no image is shown.
