Nikon DIAPHOT 300 - Page 46

3) Focusing in photomicrography
Focusing for photomicrography is carried out through the eyepieces with the
photomask built in the microscope. This applies regardless of whether the
photomicrography uses a 35mm SLR camera or a photomicrographic
attachment.
(1) Turn the reticle in/out lever to the right to bring the photomask into the optical
path.
(2) Set the turret assembly to O (eyepiece tube BT1 only). Rotate the diopter
adjustment rings of the right and left eyepieces to focus on the double
crosshairs in the photomask. (See page 29.)
(3) Use the optical path changeover dial to direct the optical path to the port on
which the camera is mounted.
Front port: B
Side port: C or D
(4) Use the coaxial coarse/fine focusing knob to bring the specimen into focus.
• High-powered objectives (40x or more)
Rotate the fine focusing knob slowly until both the double crosshairs and
specimen image are clearly seen.
• Low-powered objectives (4x~20x)
Eyepiece tube BT1 :
Use the coarse focusing knob to obtain focus. Set the turret assembly to M
(to bring the magnifier (2.5 x) into the optical path) to multiply the
microscopy magnification by the intermediate magnification. (The use of
the magnifier has no influences upon the photomicrography optical path.)
Rotate the fine focusing knob until both the double crosshairs and
specimen image are clearly seen.
NOTE: Once the magnifier is brought into the optical path, do not carry
out diopter adjustment on the eyepieces.
Eyepiece tube BT2:
Use the finder of the photomicrographic attachment, as the eyepieces are
incapable of focusing at low magnification.
Mount the focusing telescope on the finder, and looking through it, move
the focusing telescope back and forth until the double crosshairs are clearly
seen. Then, rotate the fine focusing knob to bring the double crosshairs
and specimen image into sharp focus.
(5) If a objective with a correction ring is used, make sure that the correction ring
is properly adjusted. (See page 26.)
4) Precautions on photomicrography
(1) 35mm SLR camera
• Adjust the brightness with the ND filter so that the exposure time (shutter
speed) is longer (slower) than 1/8 second. For monochrome
photomicrography, the brightness may be adjusted by varying the lamp
voltage.