Problem :
Sharp image cannot obtained
(The overall focus of picture is blurred) Possible cause :
1 Vibration)
2) Improper diopter adjustment
3) Focusing error (especially under low mag.)
4) Use thicker or thinner than 0.17mm cover glass (under high mag.)
5) Optics such as objective or photo eyepiece is dirt
6) The specimen is too thick
7) Correction collar is not properly adjusted