Setting Of Transmitted-Light Phase Contrast - Zeiss Axiotech Operating Manual

Axiotech and Axiotech
3.4.9

Setting of transmitted-light phase contrast

The phase contrast technique is ideal for the examination of thin, transparent and unstained specimens,
e.g. etching and epitaxy. The human eye is unable to recognize phase differences (differences in
refractive index and thickness) between the various specimen components.
The phase contrast technique uses the optical modulators "phase stop and phase ring" and the
interference procedures during the formation of the intermediate image to change the small phase
differences into intensity and color differences which are visible to the human eye.
Configurations
Depending on which condenser is used, the phase contrast technique requires the following modules
and can therefore only be performed with the Axiotech 30 and the Axiotech 100.
•
For the ABBE condenser 0.9/1.25 with 5-position turret disk, Cat. No. 445303-0000-000:
phase contrast objectives marked Ph 1, Ph 2 and/or Ph 3,
phase stops Ph 1, Ph 2 and/or Ph 3,
centering telescope.
•
For the ABBE condenser 0.9/1.25, Cat. No. 445302-0000-000:
phase contrast objectives marked Ph 1, Ph 2 and/or Ph 3,
plug-in phase rings Ph 1, Ph 2 and/or Ph 3,
centering telescope.
•
For the achromatic condenser 0.8 H D PH, Cat. No. 445445-9901-000:
phase contrast objectives marked Ph 1, Ph 2 and/or Ph 3,
phase stops Ph 1, Ph 2 and/or Ph 3,
centering telescope.
Centering of phase stops
• The
basic settings
brightfield described in section 3.4.6 must be
performed before the phase stops can be
centered as follows:
• Focus on the specimen in transmitted-light
brightfield, then open
diaphragm until the edge of the field of view. In
the case of low-contrast transmitted-light
specimens, it might be useful to reduce the
opening of the aperture diaphragm (move
knurled ring (3-27/1) towards 0.2 or 0.3 on the
aperture scale).
• Swing phase-contrast objective, e.g. 10 × Ph 1,
into the beam path and switch on the
appropriate phase stop Ph 1 or plug it into the
turret disk.
B 40-020 e 06/99
vario
for transmitted-light
the luminous-field
Fig. 3-27 ABBE condenser 0.9/1.25
Carl Zeiss
3-29