Operation Manual

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3.6.2 Setting the Aperture Iris Diaphragm
Ɣ The aperture iris diaphragm determines the numerical aperture of the illumination system. It has an
effect of adjusting image resolution and contrast.
Ɣ Since the contrast of microscope specimens is ordinarily low, setting the condenser aperture iris
diaphragm to between 70 and 80% of the NA of the objectives in use is usually recommended.
Ɣ Remove one of the eyepieces, look into the eyepiece sleeve and adjust the aperture iris diaphragm
ring
until the image is about 70% of objective’s exit pupil.
Ɣ You can use the condenser numerical aperture scale to adjust the aperture iris diaphragm.
Fig. 24
Fig. 25