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Using the ajustment collar on our 40x (dry) objective.

Our 40x dry Plan-Acromat objective has an adjustment collar that corrects for the differences in cover glass thicknesses, and submersion in the mounting media. This is an excerpt from the Nikon MicroscopeU web-site explaining the significance and proper use of this adjustment collar.


  1. Position the correction collar so that the indicator mark on the objective barrel coincides with the 0.17 millimeter scale mark engraved on the collar housing.
  2. Place a specimen on the stage and focus the microscope on a small specimen feature.
  3. Rotate the correction collar very slightly and re-focus the objective to determine if the image has improved or degraded. Due to the fact that most specimen preparations suffer from cover glass/media sandwiches that are too thick, start the rotation experiment by trying larger compensation values (0.18-0.23) first.
  4. Repeat the previous step to determine if the image is improving or degrading as the correction collar is turned in a single direction.
  5. If the image has degraded, follow the same steps and rotate the correction collar in the opposite direction (toward lower values) to find the position offering optimum resolution and contrast.


Last modified 2/6/04.