Brightfield / Darkfield / Phase Contrast Condenser; Brightfield Observation (Bf); Darkfield Observation (Df) - Optika Italy B-810 Serie Manuel D'instructions

10. Brightfield / Darkfield / Phase Contrast Condenser
The M-1152.NO condenser allows observation in bright field, dark field and phase contrast.
Observation mode
Phase contrast 10x
Phase contrast 20x
Phase contrast 40x
Phase contrast 100x
10.1 Brightfield Observation (BF)
1. Rotate the condenser turret to insert the "BF" position.
2. Now repeat the steps described in the chapter "Brightfield observation procedure".
10.2 Darkfield Observation (DF)
1. Rotate the condenser turret to insert the "DF"position.
• By inserting the darkfield ring, the aperture diaphragm opens automatically. This is a desired effect
and should not be considered a defect.
2. Place a specimen on the stage and focus.
3. Observing into eyepieces raise or lower the condenser until a homogeneous illumination of the specimen can
be achieved, thus obtaining a proper darkfield effect.
• Darkfield requires a huge amount of light. Switching from darkfield to brightfield, one could be
dazzled. Do not keep your eyes on the eyepieces when moving the condenser turret from DF to BF.
• "Dry" darkfield observation, that is, without the use of oil, is only possible with objectives with N.A.
lower than 0,7.
• Observing in darkfield, it may be necessary to raise the condenser from the normal position to obtain
a more homogeneous illumination. This is not a defect.
Fig. 22
Brightfield
Darkfield
Fig. 20
Fig. 23
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Fig. 21
Condenser Turret position
BF (Fig. 20)
DF (Fig. 21)
10/20 (Fig.22)
10/20 (Fig.22)
40 (Fig. 23)
100 (Fig. 24)
Fig. 24