Carl Zeiss
• Turn the knurled knob for vertical adjustment of the condenser (Fig. 4/15) until the edge of the
luminous-field diaphragm appears sufficiently sharp (Fig. 8/B).
• Center the image of the luminous-field diaphragm using both centering screws (Fig. 8/5) of the
condenser (Fig. 8/C). Then, open the diaphragm until it just disappears from the field of view
(Fig. 8/D).
• To adjust the aperture diaphragm (contrast), remove one eyepiece from the tube and look through the
tube with your naked eye. Swing lever (Fig. 8/4) to adjust the aperture diaphragm to approximately
2/3 ... 4/5 of the diameter of the exit pupil of the objective (Fig. 8/E). In most applications, this
aperture diaphragm setting provides optimum contrast at almost ideal resolution, and is therefore the
best compromise for the human eye.
• Insert the eyepiece back in the tube.
Specimen field size and objective aperture change after every objective change. Therefore,
repeat the adjustment of luminous-field diaphragm and aperture diaphragm to obtain
optimum results.
3.3.4
Adjusting transmitted-light brightfield on the Fixed Köhler microscope
The Primo Star Fixed Köhler Microscope is supplied factory-adjusted. Operation is restricted to a few
manipulations.
• Place the specimen in the specimen holder of the mechanical stage.
• If the microscope stand is equipped with a phase or dark-filed slider, pull this slider out to the left as
far as it will go.
• Adjust the desired magnification by swinging in the corresponding objective.
• Set the control lever of the aperture diaphragm of the condenser to the value of the selected
magnification (10x, 40x or 100x).
• Turn the rotary knob on the microscope stand to adjust the illumination intensity to a level pleasant
for observation.
If the condenser had been removed (e.g. for installing the illuminating mirror), make sure to
reinstall and center it by means of the two centering screws (for this, refer to Section 3.4.5).
18
Start-Up and Operation
Primo Star
B 46-0071 v 03/06