Scanning Electron Microscope
EM-30PLUS Operating Manual
81
5.4 Focus Adjustment
In order to observe specimens, set the magnification and adjust the focus exactly for clear
images.
Aperture size
As aperture gets bigger, image depth decreases due to more electrons flowed in. On the
other hand, aperture gets smaller, image depth gets deeper while image gets clearer.
WD(Working Distance)
As the value of working distance (WD) gets higher, image depth gets deeper and resolution
decreases, and when it gets smaller, images gets clearer and image depth decreases.
e.g.) Difference of depth according to WD if the size of aperture is 30um
WD: 5mm
WD: 20mm
WD 30mm
