OPERATION
Axioscope 5/7/Vario
Illumination and contrast methods in transmitted light …
ZEISS
03/2018
430035-7344-001
105
•
Then, swivel the top part of the D circular polarizer (Fig. 4-12/
2
) into the light path.
•
Rotate the lever of the
λ
/4 plate of the D circular polarizer (Fig. 4-12/
1
) until obtaining maximum
extinction (dark-gray field of view) (lever points 45° to the right).
Fig. 4-12
Components for circular polarization contrast
•
Do not view an anisotropic specimen unless the above adjustment has been done.
•
Place the specimen to be examined on the stage.
The specimens appear constantly and independently of the stage rotation in their specific interference
color, which depends on the material, specimen thickness and orientation.
NOTE
To obtain a contrast-rich image at higher objective magnifications (from approx. 20x), reduce
the illumination aperture to a value of between 0.15 and 0.20, i.e. close the aperture
diaphragm accordingly.
The effect of the
λ
/4 plate (Fig. 4-12/
2
) can be undone by either swiveling it out of the light
path or turning it with lever (Fig. 4-12/
1
) into one of its two click-stop positions.