Holey (Perforated) Carbon Film

best general TEM astigmatism check

Thin films of carbon which have been treated to obtain a large number of small holes. Supported on a G400, 400 square mesh copper Gilder grid. Examination of the Fresnel fringe around the hole when the objective lens is slightly defocused enables astigmatism to be corrected. Observation of the fringe also gives an indication of TEM stability and available resolution.

PELCO® Technical Notes, Astigmatism Correction, Holey Carbon Film (186KB PDF)