The 4-position Axio Examiner objective turret is more complicated to use than the nosepieces of most other microscopes. It's a manual turret, so there's no software or touchpad control. However, it doesn't simply freely rotate. Instead there is a dial on the front on the turret that must be rotated to the 'up' position to allow the user to rotate the objectives using the metallic ring above the dial (see gloved fingers in the image below). Rotating the dial to the 'down' position lowers the selected objective lens for imaging. When the microscope is switched off the dial should be left parked in the half way position. This ensures that the objective lens is far enough away from the stage to avoid damage, but and that the turret cannot be unintentionally rotated.
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