1. While observing a sample through the x50 objective lens, move the stage up/down by using the elevating handle to perform focal point adjustment.
2. Switch the x50 objective lens to the optional objective lens. If the focal point is displaced, remove the lens cover. You can see the adjustment ring.
3. Make sure that the focal point is properly adjusted with the x50 objective lens. Then, switch the x50 objective lens to the optional objective lens, and adjust the focal point by turning the adjustment ring.

4. After the focal point is properly adjusted with the optional lens, mount the lens cover.