9
3. Remove the eyepiece, look into the eyepiece sleeve and press the
AS – button
7
on the hand switch to set the aperture at around 70%.
4. If the center of the iris diaphragm is deviated, center it by rotating the two
AS centering screws (ƒ in Fig. 2) using the Allen screwdriver.
Fig. 4
Using the Aperture Iris Diaphragm
{In
reflected light brightfield observation
, optimum observation is gener-
ally possible by setting the aperture to between 70% and 80% of the aper-
ture number of the objective.
{In
reflected right darkfield observation
, the aperture must be fully opened
by pressing the AS + button
8
.
}With some specimens, an image with high contrast and little flare may
sometimes obtained when the aperture is slightly closed. It is therefore
recommended to also try a slightly closed aperture.
70%
7
8
30%
Aperture iris diaphragm image
