Setup
9
The phase annulus rings come pre-aligned therefore it is not necessary to adjust them before
use. Should it be necessary in the future (due to replacement of phase condenser or objectives)
follow these steps:
Aligning the Phase Contrast Annulus Rings
Center the condenser following the steps in the “Substage Adjustments” section.
Set the objectives so they are in the approximate position for actual use. This is best achieved
by placing a slide on the stage, rotating the 100X objective into position, and raising the stage
until the tip of the 100X objective is just above the slide (almost touching).
Rotate the nosepiece until the 10X objective is in the light path.
Rotate the annulus turret in the phase contrast condenser until the “10” is seen in the viewing
window.
Raise the substage all the way and completely open the aperture diaphragm as well as the
field diaphragm.
Remove an eyepiece from one of the eyetubes and replace with the phase contrast centering
telescope.
Looking through the phase contrast centering telescope, rotate the uppermost section of the
phase contrast centering telescope until the image is in focus. The image seen through the
phase contrast centering telescope should resemble rings superimposed on one another
(figures 9 & 10).
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10
Phase Contrast Models
Figure 9
Figure 10
Figure 11
Insert a small slotted screwdriver into one of the two access slots in the rear of the condenser
(figure 11) to access the adjustment screws (or preferably use two screwdrivers at the same
time, one in each access slot). While looking through the centering telescope, watch the
white ring move as you turn the adjustment screw(s) in either direction. You will need to
make adjustments to one or both of the screws in order to properly overlap the black annulus
ring with the white ring (figure 10). If you’re having problems discerning the rings from the
background or from internal reflections make sure that the telescoping eyepiece is properly
focused and that the substage height is adjusted correctly.
You will need to make this adjustment for each new phase objective or for all phase objectives
if you are replacing the phase condenser with a new one. Be sure to match the phase annulus
setting on the condenser to the appropriate phase objective when aligning.
Once the phase rings are aligned, remove the phase contrast centering telescope and
replace with the standard eyepiece.
NOTE: Brightfield work can be achieved on models with a phase contrast condenser.
The “0” setting on the phase annulus turret is used for this purpose.
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