JEM-2100plus: Objective Lens Astigmatism Correction

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Note: This page was translated by AI from the Japanese original. In case of any discrepancy, the Japanese version shall prevail.

Original post date (Japanese version): June 22, 2024

💡 This page is a quick manual for the JEM-2100plus. The contents are subject to change. Please receive training in advance before actually using the equipment.

  1. In image observation mode
  2. [PANEL-R : MAG/CAM L] Magnification setting (Low/Medium mag: x20K~ / High mag: x100K~)
  3. Beam centering
  4. Brightness adjustment
    1. [PANEL-L : BRIGHTNESS] Brightness easy for observation: Expand the beam to about the same size as the screen
  5. Focusing (Coarse/Fine)
    1. [PANEL-R : STD FOCUS] Recall reference current
    2. [PANEL-R : Z△▽] Specimen height (Z) adjustment: Lower the contrast to the minimum
    3. [PANEL-R : OBJ FOCUS] Adjust to an easy-to-see focus near the true focus
  6. Astigmatism correction
    1. Medium/Low magnification (x20K~)
      1. Observe near a hole in the film
      2. [PANEL-L : DEF/STIG : OBJ STIG] Select objective lens astigmatism adjustment mode
      3. [PANEL-R : OBJ FOCUS] Make it overfocus to display Fresnel fringes
      4. [PANEL-L/R: DEF/STIG-X/Y] Adjust so that the Fresnel fringes become isotropic
    2. High magnification (x100K~)
      1. Observe an amorphous region (such as a support film)
      2. [PANEL-L : DEF/STIG : OBJ STIG] Select objective lens astigmatism adjustment mode
      3. [PANEL-R : OBJ FOCUS] & [PANEL-L/R: DEF/STIG-X/Y]
        1. Confirm that the image flows from overfocus <> underfocus
        2. Adjust so that the image flow is minimized

      💡 Astigmatism correction on the screen (especially on the large fluorescent screen) requires practice, so normally use the camera. You may use binoculars and the small fluorescent screen, but using the camera + FFT is easier.

*This post was created by an AI agent.