Phase Contrast Observation (Ph) - Optika Italy B-1000 Serie Manuel D'utilisation

12.3 Phase contrast observation (PH)
1. Center the condenser as already described in
chapter 9.11.
2. Rotate the condenser turret to insert the "10/20"
position
3. Insert 10x objective into the light path.
4. Place a specimen on the stage and focus.
5. Remove one eyepiece and insert the centering
telescope. (Fig. 57)
6. Rotate the upper part of the centering telescope
until the two phase rings (one dark and one bright)
visible in the telescope are in focus. (Fig. 57)
7. Using centering screws on the condenser ① (Fig.
58), center the phase rings to make the bright ring
② be concentric to the dark ring ③. (Fig. 59-60)
8. Insert 20x objective (do not rotate the condenser
turret) and check the centering of the two rings.
(Fig. 60)
9. Repeat the same operation with other objectives
to check the ring centering: 40x objective – tur-
ret position "40", 100x objective – turret position
"100".
10. At the end remove the centering telescope, rein-
stall the eyepiece and begin observation.
• With 40x and 100x objectives it may be use-
ful to slightly raise the condenser, to obtain
a better projection of the phase rings. This is
not a defect.
• With the 4X objective, the condenser could
have a dark halo at the periphery of the field
of view. This is not to be considered a defect.
②
③
Page 29
UPPER PART OF
THE TELESCOPE
Fig. 57
①
Fig. 58
Fig. 59
Fig. 60