Nikon DIAPHOT 300 - Turret Assembly.28

9. Turret Assembly (For Eyepiece Tube BT1 only)
The turret assembly has four positions, 0, B, C and M. Use them selectively. Use
position 0 for normal microscopy.
0: The optical path is becomes hollow.
B : The Bertrand lens enters the optical path, enabling you to observe the exit
pupil of the objective. Thus, this position allows centering of the phase
contrast annular diaphragm and aperture adjustment of the condenser aperture
diaphragm. Use the Bertrand lens focusing screw for focusing.
C : The light blocking plate enters the optical path, shielding the external light from
the eyepiece. This position is used for photomicrography.
M: The magnifier lens enters the optical path, applying the 2.5x intermediate
magnification to the observation system. This position is used for observation
at slightly higher magnification, or for focusing in photomicrography using the
4x~20x objective.
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